Fire-Class Reinforced Aerogel Compositions

ABSTRACT

The current disclosure provides reinforced aerogel compositions that are durable and easy to handle, have favorable performance in aqueous environments, have favorable insulation properties, and have favorable, reaction to fire, combustion and flame-resistance properties. Also provided are methods of preparing or manufacturing such reinforced aerogel compositions. In certain embodiments, the composition has a silica-based aerogel framework, reinforced with an open-cell macroporous framework, and includes one or more fire-class additives, where the silica-based aerogel framework comprises at least one hydrophobic-bound silicon and the composition or each of its components has desired properties.

CROSS-REFERENCES TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application. Ser. No.16/425,825, filed on May 29, 2019 and which claims the benefit ofpriority from U.S. Provisional Patent Application No. 62/678,850 filedon May 31, 2018, both of which are incorporated herein by reference intheir entireties, with any definition of terms in the presentapplication controlling.

BACKGROUND OF THE INVENTION 1. Field of the Invention

This invention relates, generally, to aerogel technology. Morespecifically, it relates to aerogel compositions with fire-classadditives.

2. Brief Description of the Related Art

Low-density aerogel materials are widely considered to be the best solidinsulators available. Aerogels function as insulators primarily byminimizing conduction (low structural density results in tortuous pathfor energy transfer through the solid framework), convection (large porevolumes and very small pore sizes result in minimal convection), andradiation (IR absorbing or scattering dopants are readily dispersedthroughout the aerogel matrix). Aerogels can be used in a broad range ofapplications, including heating and cooling insulation, acousticsinsulation, electronic dielectrics, aerospace, energy storage andproduction, and filtration. Furthermore, aerogel materials display manyother interesting acoustic, optical, mechanical, and chemical propertiesthat make them abundantly useful in various insulation andnon-insulation applications.

However, what are needed are fire-class reinforced aerogel compositionswith improved performance in various aspects, including in thermalresistance, hydrophobicity, fire reaction and others, individually andin one or more combinations. In view of the art considered as a whole atthe time the present invention was made, though, it was not obvious tothose of ordinary skill in the field of this invention how theshortcomings of the prior art could be overcome.

While certain aspects of conventional technologies have been discussedto facilitate disclosure of the invention, Applicants in no way disclaimthese technical aspects, and it is contemplated that the claimedinvention may encompass one or more of the conventional technicalaspects discussed herein.

The present invention may address one or more of the problems anddeficiencies of the prior art. However, it is contemplated that theinvention may prove useful in addressing other problems and deficienciesin a number of technical areas. Therefore, the claimed invention shouldnot necessarily be construed as limited to addressing any of theparticular problems or deficiencies discussed herein.

In this specification, where a document, act or item of knowledge isreferred to or discussed, this reference or discussion is not anadmission that the document, act or item of knowledge or any combinationthereof was at the priority date, publicly available, known to thepublic, part of common general knowledge, or otherwise constitutes priorart under the applicable statutory provisions; or is known to berelevant to an attempt to solve any problem with which thisspecification is concerned.

BRIEF SUMMARY OF THE INVENTION

The long-standing but heretofore unfulfilled need for improved aerogelcompositions is now met by a new, useful, and nonobvious invention.

In an embodiment, the current invention is a reinforced aerogelcomposition comprising a silica-based aerogel framework, reinforced withan open-cell macroporous framework (“OCMF”) material, and a fire-classadditive, where the silica-based aerogel framework comprises at leastone hydrophobic-bound silicon.

In one general aspect, the present disclosure provides reinforcedaerogel compositions that are durable and easy to handle, which hasfavorable performance in aqueous environments, which has favorableinsulation properties, and that also has favorable combustion andflame-resistance properties. In certain embodiments, the presentdisclosure presents a reinforced aerogel composition that is reinforcedwith an OCMF, which has favorable performance in aqueous environments,which has favorable insulation properties, and that also has favorablecombustion and flame-resistance properties.

In another general aspect, the present disclosure provides a reinforcedaerogel composition comprising a silica-based aerogel framework and anOCMF, and which has the following properties: a) a thermal conductivityof 30 mW/m*K or less; b) a liquid water uptake of 30 wt % or less; andc) a heat of combustion of 717 cal/g or less. In certain embodiments, areinforced aerogel composition of the present disclosure has thefollowing properties: a) a thermal conductivity of 25 mW/m*K or less; b)a liquid water uptake of 20 wt % or less; and c) a heat of combustion of717 cal/g or less. In certain embodiments, a reinforced aerogelcomposition of the present disclosure has a density of 0.40 g/cm3 orless, 0.30 g/cm3 or less, 0.25 g/cm3 or less, or 0.20 g/cm3 or less. Incertain embodiments, reinforced aerogel compositions of the presentdisclosure have a thermal conductivity of 25 mW/M*K or less, 20 mW/M*Kor less, 18 mW/M*K or less, a thermal conductivity between 15 mW/M*K and30 mW/M*K, or a thermal conductivity between 15 mW/M*K and 20 mW/M*K. Incertain embodiments, a reinforced aerogel composition of the presentdisclosure has a liquid water uptake of 30 wt % or less, 25 wt % orless, 20 wt % or less, 15 wt % or less, 10 wt % or less, or 5 wt % orless. In certain embodiments, a reinforced aerogel composition of thepresent disclosure has a heat of combustion of 717 cal/g or less, 700cal/g or less, 675 cal/g or less, 650 cal/g or less, 625 cal/g or less,600 cal/g or less, or a heat of combustion between 580 cal/g and 717cal/g. In certain specific aspects, combination of the values describedabove in thermal conductivity, water uptake and heat of combustion areachieved by varying gel precursor composition, additive composition,catalyst or other agents that activate the precursor, pH of theprecursor solution, dispensing rate, respectively of precursors,catalyst or additives, time allowed for gelation to take place, windingof gel (in certain aspects), ageing time and pH, any post-gelationtreatment, extraction time and conditions (temperature, pressure) andany subsequent drying steps.

In another general aspect, the present disclosure provides reinforcedaerogel compositions comprising a silica-based aerogel framework, amelamine-based OCMF, and a fire-class additive, and has the followingproperties: a) a thermal conductivity between 15 mW/M*K and 30 mW/M*K;b) a liquid water uptake of 30 wt % or less; and c) a heat of combustionbetween 580 cal/g and 717 cal/g. In a certain preferred embodiments, theOCMF material is an organic OCMF material. In another certain preferredembodiments, the OCMF material is a melamine-based OCMF material. Incertain embodiments, a reinforced aerogel compositions of the presentdisclosure has a hydrophobic organic content between about 1 wt % andabout 30 wt %, between about 1 wt % and about 25 wt %, between about 1wt % and about 20 wt %, between about 1 wt % and about 15 wt %, betweenabout 1 wt % and about 10 wt %, or between about 1 wt % and about 5 wt%.

In another general aspect, the present disclosure provides a method ofpreparing a reinforced aerogel composition, comprising a) providing aprecursor solution comprising silica gel precursor materials, a solvent,and optionally a catalyst; b) combining the precursor solution with areinforcement material comprising an OCMF; c) allowing the silica gelprecursor materials in the precursor solution to transition into a gelmaterial or composition; and d) extracting at least a portion of thesolvent from the gel material or composition to obtain an aerogelmaterial or composition. In certain embodiments, methods of the presentdisclosure include incorporating a fire-class additive material into thereinforced aerogel composition by combining the fire-class additivematerial with the precursor solution either before or during thetransition of the silica gel precursor materials in the precursorsolution into the gel composition. In a preferred embodiment, thereinforcement material comprises a melamine-based OCMF material. Incertain embodiments, methods of the present disclosure includeincorporating at least one hydrophobic-bound silicon into the aerogelmaterial or composition by one or both of the following: i) including inthe precursor solution at least one silica gel precursor material havingat least one hydrophobic group, or ii) exposing the precursor solution,gel composition, or aerogel composition to a hydrophobizing agent. Incertain embodiments, methods of the present disclosure include the stepof incorporating at least one hydrophobic-bound silicon into the aerogelcomposition providing a hydrophobic organic content in the aerogelcomposition of between about 1 wt % and about 25 wt %, between about 1wt % and about 20 wt %, between about 1 wt % and about 15 wt %, betweenabout 1 wt % and about 10 wt %, or between about 1 wt % and about 5 wt%. In a preferred embodiment, methods of the present disclosure producea reinforced aerogel composition. In certain embodiments, methods of thepresent disclosure produce a reinforced aerogel composition comprising asilica-based aerogel framework, a melamine-based OCMF, and a fire-classadditive, and which has the following properties: a) a thermalconductivity between 15 mW/M*K and 30 mW/M*K; b) a liquid water uptakeof 30 wt % or less; and c) a heat of combustion between 580 cal/g and717 cal/g.

Additionally, the following specific, non-limiting embodiments/examplesare disclosed. The enumerated examples are presented to illustrate acertain range of embodiments that are contemplated herein, including acombination of such embodiments or examples. The invention as describedin the claims have scope beyond these non-limiting examples.

Embodiment 1 is a reinforced aerogel composition comprising asilica-based aerogel framework, reinforced with an OCMF material, and afire-class additive; wherein the silica-based aerogel frameworkcomprises at least one hydrophobic-bound silicon; and wherein thereinforced aerogel composition has the following properties: i) liquidwater uptake of 20 wt % or less; ii) thermal conductivity of 30 mW/M*Kor less; and iii) heat of combustion of less than 717 cal/g.

Embodiment 2 is a reinforced aerogel composition comprising asilica-based aerogel framework, reinforced with an OCMF material with adensity of between 2 kg/m³ and 25 kg/m³, and a fire-class additive;wherein the silica-based aerogel framework comprises at least onehydrophobic-bound silicon; and wherein the reinforced aerogelcomposition has the following properties: i) liquid water uptake of 20wt % or less; ii) thermal conductivity of 30 mW/M*K or less; and iii)heat of combustion of less than 717 cal/g.

Embodiment 3 is a reinforced aerogel composition comprising asilica-based aerogel framework, reinforced with an OCMF material with adensity of 2 kg/m³ and 25 kg/m³, and a fire-class additive; wherein thesilica-based aerogel framework comprises at least one hydrophobic-boundsilicon; and wherein the reinforced aerogel composition has thefollowing properties: i) liquid water uptake of between 1 wt % and 10 wt%; ii) thermal conductivity of more than 8 and less than 25 mW/M*K; andiii) heat of combustion of less than 717 cal/g and more than 400 cal/g.

Embodiment 4 is a reinforced OCMF composition reinforced with asilica-based aerogel composition and a fire class additive; wherein thesilica-based aerogel framework comprises at least one hydrophobic-boundsilicon; and wherein the reinforced aerogel composition has thefollowing properties: i) liquid water uptake of 20 wt % or less; ii)thermal conductivity of 30 mW/M*K or less; and iii) heat of combustionof less than 717 cal/g.

Embodiment 5 is a reinforced OCMF composition reinforced with asilica-based aerogel composition and a fire class additive; wherein thesilica-based aerogel framework comprises at least one hydrophobic-boundsilicon; and wherein the reinforced aerogel composition has thefollowing properties: i) liquid water uptake of 20 wt % or less; ii)thermal conductivity of 30 mW/M*K or less; and iii) heat of combustionof less than 717 cal/g.

Embodiment 6 is a reinforced OCMF composition reinforced with asilica-based aerogel composition and a fire class additive; wherein thesilica-based aerogel framework comprises at least one hydrophobic-boundsilicon; and wherein the reinforced aerogel composition has thefollowing properties: i) liquid water uptake of between 1 wt % and 10 wt%; ii) thermal conductivity of more than 8 and less than 25 mW/M*K; andiii) heat of combustion of less than 717 cal/g and more than 400 cal/g.

Embodiment 7 is a set of embodiments with the reinforced aerogelcomposition of any one of embodiments 1-3 or reinforced OCMF compositionof any one of embodiments 4-6, wherein the OCMF material comprises or isan organic OCMF material.

Embodiment 8 is a set of embodiments with the reinforced aerogelcomposition of any one of embodiments 1-3 or reinforced OCMF compositionof any one of embodiments 4-6, wherein the OCMF material comprises or isa melamine based OCMF material.

Embodiment 9 is a set of embodiments with the reinforced aerogelcomposition of any one of embodiment 1-3 or reinforced OCMF compositionof any one of embodiments 4-6, wherein the OCMF material comprises or isa sheet of OCMF material.

Embodiment 10 is a set of embodiments with the reinforced aerogelcomposition of any one of embodiment 1-3 or reinforced OCMF compositionof any one of embodiments 4-6, wherein the OCMF material is an organicfoam.

Embodiment 11 is a set of embodiments with the reinforced aerogelcomposition of any one of embodiment 1-3 or reinforced OCMF compositionof any one of embodiments 4-6, wherein the OCMF material is a melaminebased foam.

Embodiment 12 is a set of embodiments with the reinforced aerogelcomposition or reinforced OCMF composition of any one of embodiments1-11, wherein the OCMF material is neither a low-combustible materialnor a non-combustible material.

Embodiment 13 is a set of embodiments with the reinforced aerogelcomposition or reinforced OCMF composition of any one of embodiments1-11, wherein the OCMF material is neither a low-flammable material nora non-flammable material.

Embodiment 14 is a set of embodiments with the reinforced aerogelcomposition or reinforced OCMF composition of any one of embodiments1-11, wherein the OCMF material comprises between 2 wt % and 10 wt % ofthe composition.

Embodiment 15 is a set of embodiments with the reinforced aerogelcomposition or reinforced OCMF composition of any one of embodiments1-14, wherein the hydrophobic silicon-bound content in the compositionis between 2 wt % and 10 wt %.

Embodiment 16 is a set of embodiments with the reinforced aerogelcomposition or reinforced OCMF composition of any one of embodiments1-14, wherein the hydrophobic silicon-bound content in the compositionis between 2 wt % and 8 wt %.

Embodiment 17 is a set of embodiments with the reinforced aerogelcomposition or reinforced OCMF composition of any one of embodiments1-14, wherein the hydrophobic silicon-bound content in the compositionis between 2 wt % and 6 wt %.

Embodiment 18 is a set of embodiments with the reinforced aerogelcomposition or reinforced OCMF composition of any one of embodiments1-17, wherein the composition has a heat of combustion of 700 cal/g orless.

Embodiment 19 is a set of embodiments with the reinforced aerogelcomposition or reinforced OCMF composition of any one of embodiments1-17, wherein the composition has a heat of combustion of 675 cal/g orless.

Embodiment 20 is a set of embodiments with the reinforced aerogelcomposition or reinforced OCMF composition of any one of embodiments1-17, wherein the composition has a heat of combustion of 650 cal/g orless.

Embodiment 21 is a set of embodiments with the reinforced aerogelcomposition or reinforced OCMF composition of any one of embodiments1-17, wherein the composition has a heat of combustion of 625 cal/g orless.

Embodiment 22 is a set of embodiments with the reinforced aerogelcomposition or reinforced OCMF composition of any one of embodiments1-21, wherein the composition has a thermal conductivity of 22 mW/M*K orless.

Embodiment 23 is a set of embodiments with the reinforced aerogelcomposition or reinforced OCMF composition of any one of embodiments1-21, wherein the reinforced aerogel composition has a thermalconductivity of 20 mW/M*K or less.

Embodiment 24 is a set of embodiments with the reinforced aerogelcomposition or reinforced OCMF composition of any one of embodiments1-21, wherein the reinforced aerogel composition has a thermalconductivity of 18 mW/M*K or less.

Embodiment 25 is a set of embodiments with the reinforced aerogelcomposition or reinforced OCMF composition of any one of embodiments1-21, wherein the reinforced aerogel composition has a density between0.15 and 0.40 g/cm3.

Embodiment 26 is a set of embodiments with the reinforced aerogelcomposition or reinforced OCMF composition of any one of embodiments1-21, wherein the reinforced aerogel composition has an onset of thermaldecomposition of 350° C. or above.

Embodiment 27 is a set of embodiments with the reinforced aerogelcomposition or reinforced OCMF composition of any one of embodiments1-21, wherein the reinforced aerogel composition has an onset of thermaldecomposition of 360° C. or above.

Embodiment 28 is a set of embodiments with the reinforced aerogelcomposition or reinforced OCMF composition of any one of embodiments1-21, wherein the reinforced aerogel composition has an onset of thermaldecomposition of 370° C. or above.

Embodiment 29 is a set of embodiments with the reinforced aerogelcomposition or reinforced OCMF composition of any one of embodiments1-21, wherein the reinforced aerogel composition has an onset of thermaldecomposition of 380° C. or above.

Embodiment 30 is a set of embodiments with the reinforced aerogelcomposition or reinforced OCMF composition of any one of embodiments1-21, wherein the reinforced aerogel composition has an onset of thermaldecomposition of 390° C. or above.

Embodiment 31 is an organic OCMF reinforced aerogel compositioncomprising fire class additives and hydrophobic organic content whereinthe onset of endothermic decomposition of the fire class additives inthe composition is within 50 degrees Celsius of the onset of thermaldecomposition of the rest of the composition without the fire classadditive.

Embodiment 32 is an organic OCMF reinforced aerogel compositioncomprising fire class additives and hydrophobic content of at least 5%wherein the total heat of endothermic decomposition of the fire classadditives in the composition is at least 30% of the exothermic heat ofdecomposition of the rest of the composition without the fire classadditive.

Embodiment 33 is an organic OCMF reinforced aerogel compositioncomprising at least two fire class additives with their respective onsetof endothermic decomposition are at least 10 degrees Celsius apart.

Embodiment 34 is an organic OCMF reinforced aerogel compositioncomprising fire class additives and hydrophobic content wherein thetotal heat of endothermic decomposition of the fire class additives inthe composition is no more than 80% of the exothermic heat ofdecomposition of the rest of the composition without the fire classadditive.

Embodiment 35 is a set of embodiments with the reinforced aerogelcomposition or reinforced OCMF composition of any one of embodiments1-11, wherein the hydrophobic content is at least 5% and the total heatof endothermic decomposition of the fire class additives in thecomposition is at least 30% of the exothermic heat of decomposition ofthe rest of the composition without the fire class additive.

Embodiment 36 is a set of embodiments with the reinforced aerogelcomposition or reinforced OCMF composition of any one of embodiments1-11, wherein the onset of endothermic decomposition of the fire classadditives in the composition is within 50 degrees Celsius of the onsetof thermal decomposition of the rest of the composition without the fireclass additive.

Embodiment 37 is a set of embodiments with the reinforced aerogelcomposition or reinforced OCMF composition of any one of embodiments1-11, with at least two fire class additives wherein the two fire classadditives respective onset of endothermic decomposition are at least 10degrees Celsius apart.

Embodiment 38 is a set of embodiments with the reinforced aerogelcomposition or reinforced OCMF composition of any one of embodiments1-11, wherein the total heat of endothermic decomposition of the fireclass additives in the composition is no more than 80% of the exothermicheat of decomposition of the rest of the composition without the fireclass additive.

Embodiment 39 is a set of embodiments with the composition of any one ofembodiments 1-38, wherein the furnace temperature rise of thecomposition in accordance with ISO 1182 is about 100° C. or less, about90° C. or less, about 80° C. or less, about 70° C. or less, about 60° C.or less, about 50° C. or less, about 45° C. or less, about 40° C. orless, about 38° C. or less, about 36° C. or less, about 34° C. or less,about 32° C. or less, about 30° C. or less, about 28° C. or less, about26° C. or less, about 24° C. or less, or in a range between any two ofthese values.

Embodiment 40 is a set of embodiments with the composition of any one ofembodiments 1-39, wherein the flame time of the composition inaccordance with ISO 1182 is about 30 seconds or less, about 25 secondsor less, about 20 seconds or less, about 15 seconds or less, about 10seconds or less, about 5 seconds or less, about 2 seconds or less, or ina range between any two of these values.

Embodiment 41 is a set of embodiments with the composition of any one ofembodiments 1-40, wherein the mass loss of the composition in accordancewith ISO 1182 is about 50% or less, about 40% or less, about 30% orless, about 28% or less, about 26% or less, about 24% or less, about 22%or less, about 20% or less, about 18% or less, about 16% or less, or ina range between any two of these values.

Embodiment 42 is a set of embodiments with the composition of any one ofthe above embodiments, wherein the composition is low-flammable.

Embodiment 43 is a set of embodiments with the composition of any one ofthe above embodiments, wherein the composition is non-flammable.

Embodiment 44 is a set of embodiments with the composition of any one ofthe above embodiments, wherein the composition is low-combustible.

Embodiment 45 is a set of embodiments with the composition of any one ofthe above embodiments, wherein the composition is non-combustible.

Embodiment 46 is a set of embodiments with the composition of any one ofthe above embodiments, wherein the onset of endothermic decomposition ofthe fire class additive is greater than 280° C., 300° C., 350° C., 400°C., 450° C. or 500° C.

Embodiment 47 is a set of embodiments with the composition of any one ofthe above embodiments, wherein the onset of exothermic decomposition ofthe composition without the fire class additive is greater than 280° C.,300° C., 350° C., 400° C., 450° C. or 500° C.

Embodiment 48 is a set of embodiments with the composition of any one ofthe above embodiments, wherein the OCMF material is a melamine basedfoam.

Embodiment 49 is a set of embodiments with the composition of any one ofthe above embodiments, wherein the OCMF material is a urethane basedpolymer foam.

Embodiment 50 is a set of embodiments with the composition of any one ofthe above claims, wherein the OCMF material is a reticulated foam.

Furthermore, aerogel materials or framework of the various embodimentsof the present invention may also be practiced with aerogel particlebased slurries or suspensions infiltrated into the OCMF materialsdescribed in various embodiments. In yet another embodiment, variousembodiments of the present invention may be practiced withnon-particulate aerogel materials produced in-situ by infiltrating theOCMF materials with various gel precursors in suitable solvent andfollowed by the removal of the solvent using various methods, includingusing supercritical fluids, or at elevated temperatures and ambientpressures or at sub-critical pressures.

In separate embodiments, the current invention includes a reinforcedaerogel composition or OCMF-reinforced composition, comprising one ormore—or even all—of the foregoing features and characteristics,including various combinations and methods of manufacture thereof.

These and other important objects, advantages, and features of theinvention will become clear as this disclosure proceeds.

The invention accordingly comprises the features of construction,combination of elements, and arrangement of parts that will beexemplified in the disclosure set forth hereinafter and the scope of theinvention will be indicated in the claims.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 depicts thermogravimetric analysis (TGA) and differentialscanning calorimetry (DSC) measurements for an aerogel compositionwithout any additives, a hydrophobic aerogel composition of the presentinvention reinforced with melamine foam, with about 120% of magnesiumhydroxide, with 100% reference being the weight of silica and hydrophobeconstituents of the aerogel composition (Example 3).

FIG. 2 depicts thermogravimetric analysis (TGA) and differentialscanning calorimetry (DSC) measurements for an aerogel compositionwithout any additives, a hydrophobic aerogel composition of the presentinvention reinforced with melamine foam, with about 120% of halloysiteclay, with 100% reference being the weight of silica and hydrophobeconstituents of the aerogel composition (Example 21).

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

In the following detailed description of the preferred embodiments,reference is made to the accompanying drawings, which form a partthereof, and within which are shown by way of illustration specificembodiments by which the invention may be practiced. It is to beunderstood that other embodiments may be utilized and structural changesmay be made without departing from the scope of the invention.

As used in this specification and the appended claims, the singularforms “a”, “an”, and “the” include plural referents unless the contentclearly dictates otherwise. As used in this specification and theappended claims, the term “or” is generally employed in its senseincluding “and/or” unless the context clearly dictates otherwise.

As used herein, “about” means approximately or nearly and in the contextof a numerical value or range set forth means ±15% of the numerical. Inan embodiment, the term “about” can include traditional roundingaccording to significant figures of the numerical value. In addition,the phrase “about ‘x’ to ‘y’” includes “about ‘x’ to about ‘y’”.

As used herein, the terms “composition” and “composite” are usedinterchangeably.

Aerogels are a class of porous materials with open-cells comprising aframework of interconnected structures, with a corresponding network ofpores integrated within the framework, and an interstitial phase withinthe network of pores primarily comprised of gases such as air. Aerogelsare typically characterized by a low density, a high porosity, a largesurface area, and small pore sizes. Aerogels can be distinguished fromother porous materials by their physical and structural properties.

Within the context of the present disclosure, the term “aerogel” or“aerogel material” refers to a gel comprising a framework ofinterconnected structures, with a corresponding network ofinterconnected pores integrated within the framework, and containinggases such as air as a dispersed interstitial medium; and which ischaracterized by the following physical and structural properties(according to Nitrogen Porosimetry Testing) attributable to aerogels:(a) an average pore diameter ranging from about 2 nm to about 100 nm,(b) a porosity of at least 80% or more, and (c) a surface area of about20 m²/g or more.

Aerogel materials of the present disclosure thus include any aerogels orother open-celled compounds which satisfy the defining elements setforth in previous paragraphs; including compounds which can be otherwisecategorized as xerogels, cryogels, ambigels, microporous materials, andthe like.

Aerogel materials may also be further characterized by additionalphysical properties, including: (d) a pore volume of about 2.0 mL/g ormore, particularly about 3.0 mL/g or more; (e) a density of about 0.50g/cc or less, particularly about 0.25 g/cc or less; and (f) at least 50%of the total pore volume comprising pores having a pore diameter ofbetween 2 and 50 nm; though satisfaction of these additional propertiesis not required for the characterization of a compound as an aerogelmaterial.

Within the context of the present disclosure, the term “innovativeprocessing and extraction techniques” refers to methods of replacing aliquid interstitial phase in a wet-gel material with a gas such as air,in a manner which causes low pore collapse and low shrinkage to theframework structure of the gel. Drying techniques, such as ambientpressure evaporation, often introduce strong capillary pressures andother mass transfer limitations at the liquid-vapor interface of theinterstitial phase being evaporated or removed. The strong capillaryforces generated by liquid evaporation or removal can cause significantpore shrinkage and framework collapse within the gel material. The useof innovative processing and extraction techniques during the extractionof a liquid interstitial phase reduces the negative effects of capillaryforces on the pores and the framework of a gel during liquid extraction(also referred to as solvent removal or drying).

In certain embodiments, an innovative processing and extractiontechnique uses near critical or super critical fluids, or near criticalor super critical conditions, to extract the liquid interstitial phasefrom a wet-gel material. This can be accomplished by removing the liquidinterstitial phase from the gel near or above the critical point of theliquid or mixture of liquids. Co-solvents and solvent exchanges can beused to optimize the near critical or super critical fluid extractionprocess.

In certain embodiments, an innovative processing and extractiontechnique includes the modification of the gel framework to reduce theirreversible effects of capillary pressures and other mass transferlimitations at the liquid-vapor interface. This embodiment can includethe treatment of a gel framework with a hydrophobizing agent, or otherfunctionalizing agents, which allow a gel framework to withstand orrecover from any collapsing forces during liquid extraction conductedbelow the critical point of the liquid interstitial phase. Thisembodiment can also include the incorporation of functional groups orframework elements, which provide a framework modulus that issufficiently high to withstand or recover from collapsing forces duringliquid extraction conducted below the critical point of the liquidinterstitial phase.

Within the context of the present disclosure, the terms “framework” or“framework structure” refer to a network of interconnected oligomers,polymers, or particles that form the solid structure of a material.Within the context of the present disclosure, the terms “aerogelframework” or “aerogel framework structure” refer to the network ofinterconnected oligomers, polymers, or colloidal particles that form thesolid structure of a gel or an aerogel. The polymers or particles thatmake up the aerogel framework structure typically have a diameter ofabout 100 angstroms. However, framework structures of the presentdisclosure may also include networks of interconnected oligomers,polymers, or colloidal particles of all diameter sizes that form thesolid structure within a material such as a gel or aerogel. Furthermore,the terms “silica-based aerogel” or “silica-based aerogel framework”refer to an aerogel framework in which silica comprises at least 50% (byweight) of the oligomers, polymers, or colloidal particles that form thesolid framework structure within in the gel or aerogel.

Within the context of the present disclosure, the term “aerogelcomposition” refers to any composite material that includes aerogelmaterial as a component of the composite. Examples of aerogelcompositions include, but are not limited to fiber-reinforced aerogelcomposites; aerogel composites which include additive elements such asopacifiers; aerogel composites reinforced by open-cell macroporousframeworks; aerogel-polymer composites; and composite materials whichincorporate aerogel particulates, particles, granules, beads, or powdersinto a solid or semi-solid material, such as binders, resins, cements,foams, polymers, or similar solid materials. Aerogel compositions aregenerally obtained after the removal of the solvent from various gelmaterials disclosed in this invention. Aerogel compositions thusobtained may further be subjected to additional processing or treatment.The various gel materials may also be subjected to additional processingor treatment otherwise known or useful in the art before subjected tosolvent removal (or liquid extraction or drying).

Within the context of the present disclosure, the term “monolithic”refers to aerogel materials in which a majority (by weight) of theaerogel included in the aerogel material or composition is in the formof a unitary interconnected aerogel nanostructure. Monolithic aerogelmaterials include aerogel materials which are initially formed to have aunitary interconnected gel or aerogel nanostructure, but which aresubsequently cracked, fractured, or segmented into non-unitary aerogelnanostructures. Monolithic aerogel materials are differentiated fromparticulate aerogel materials. The term “particulate aerogel material”refers to aerogel materials in which a majority (by weight) of theaerogel included in the aerogel material is in the form of particulates,particles, granules, beads, or powders, which can be combined orcompressed together but which lack an interconnected aerogelnanostructure between individual particles.

Within the context of the present disclosure, the term “wet gel” refersto a gel in which the mobile interstitial phase within the network ofinterconnected pores is primarily comprised of a liquid, such as aconventional solvent, liquefied gases like liquid carbon dioxide, or acombination thereof. Aerogels typically require the initial productionof a wet gel, followed by innovative processing and extraction toreplace the mobile interstitial liquid in the gel with air. Examples ofwet gels include, but are not limited to alcogels, hydrogels, ketogels,carbonogels, and any other wet gels known to those in the art.

Aerogel compositions of the present disclosure may comprise reinforcedaerogel compositions. Within the context of the present disclosure, theterm “reinforced aerogel composition” refers to aerogel compositionscomprising a reinforcing phase within the aerogel material, where thereinforcing phase is not part of the aerogel framework itself. Thereinforcing phase may be any material that provides increasedflexibility, resilience, conformability, or structural stability to theaerogel material. Examples of well-known reinforcing materials include,but are not limited to open-cell macroporous framework reinforcementmaterials, closed-cell macroporous framework reinforcement materials,open-cell membranes, honeycomb reinforcement materials, polymericreinforcement materials, and fiber reinforcement materials such asdiscrete fibers, woven materials, non-woven materials, needlednon-wovens, battings, webs, mats, and felts.

Reinforced aerogel compositions of the present disclosure may compriseaerogel compositions reinforced with open-cell macroporous frameworkmaterials. Within the context of the present disclosure, the term“open-cell macroporous framework” or “OCMF” refers to a porous materialcomprising a framework of interconnected structures of substantiallyuniform composition, with a corresponding network of interconnectedpores integrated within the framework; and which is characterized by anaverage pore diameter ranging from about 10 μm to about 700 μm Suchaverage pore diameter may be measured by known techniques, including butnot limited to, Microscopy with optical analysis. OCMF materials of thepresent disclosure thus include any open-celled materials that satisfythe defining elements set forth in this paragraph, including compoundsthat can be otherwise categorized as foams, foam-like materials,macroporous materials, and the like. OCMF materials can bedifferentiated from materials comprising a framework of interconnectedstructures that have a void volume within the framework and that do nothave a uniform composition, such as collections of fibers and bindershaving a void volume within the fiber matrix.

Within the context of the present disclosure, the term “substantiallyuniform composition” refers to uniformity in the composition of thereferred material within 10% tolerance.

Within the context of the present disclosure, the term “OCMF-reinforcedaerogel composition” refers to a reinforced aerogel compositioncomprising an open-cell macroporous framework material as a reinforcingphase. Suitable OCMF materials for use in the present disclosureinclude, but are not limited to, OCMF materials made from organicpolymeric materials. Examples include OCMF materials made frompolyolefins, polyurethanes, phenolics, melamine, cellulose acetate, andpolystyrene. Within the context of the present disclosure, the term“organic OCMF” refers to OCMF materials having a framework comprisedprimarily of organic polymeric materials. OCMF materials made frommelamine or melamine derivatives are also preferred in certainembodiments. Within the context of the present disclosure, the terms“melamine OCMF” or “melamine-based OCMF” refer to organic OCMF materialshaving a framework comprised primarily of polymeric materials derivedfrom reacting melamine with a condensation agent, such as formaldehyde.Examples of OCMF materials made from melamine or melamine derivativesfor use in the present disclosure are presented in U.S. Pat. Nos.8,546,457, 4,666,948, and WO 2001/094436. The term “inorganic OCMF”refers to OCMF materials having a framework comprised primarily ofinorganic materials. Examples of inorganic OCMF include, but not limitedto, cementous materials, gypsum, and calcium silicate.

Within the context of the present invention, the term “foam” refers to amaterial comprising a framework of interconnected polymeric structuresof substantially uniform composition, with a corresponding network orcollection of pores integrated within the framework, and which is formedby dispersing a proportion of gas in the form of bubbles into a liquidor resin foam material such that the gas bubbles are retained as poresas the foam material solidifies into a solid structure. In general,foams can be made using a wide variety of processes—see, for example,U.S. Pat. Nos. 6,147,134; 5,889,071; 6,187,831; and 5,229,429. Foammaterials of the present disclosure thus include any materials thatsatisfy the defining elements set forth in this paragraph, includingcompounds that can be otherwise categorized as OCMF materials,macroporous materials, and the like. Foams as defined in the presentinvention may be in the types of thermoplastics, elastomers, andthermosets (duromers).

The pores within a solid framework can also be referred to as “cells”.Cells can be divided by cell walls or membranes, creating a collectionof independent closed pores within the porous material. The term “closedcell” refers to porous materials in which at least 50% of the porevolume is [substantially] confined cells enclosed by membranes or walls.Cells in a material can also be interconnected through cell openings,creating a network of interconnected open pores within the material. Theterm “open cell” refers to porous materials in which at least 50% of thepore volume is open cells. The open-cell material may comprise areticulated open-cell material, a non-reticulated open-cell material, ora combination thereof. Reticulated materials are open cell materialsproduced through a reticulation process that eliminates or puncturescell membranes within the porous material. Reticulated materialstypically have a higher concentration of open cells than non-reticulatedmaterials, but tend to be more expensive and difficult to produce.Generally, no porous material has entirely one type of cell structure(open cell or closed cell). Porous materials may be made using a widevariety of processes, including foam production processes presented inU.S. Pat. Nos. 6,147,134, 5,889,071, 6,187,831, 5,229,429, 4,454,248,and US Patent Application No 20070213417.

Within the context of the present disclosure, the terms “aerogelblanket” or “aerogel blanket composition” refer to aerogel compositionsreinforced with a continuous sheet of reinforcement material. Aerogelblanket compositions can be differentiated from other reinforced aerogelcompositions that are reinforced with a non-continuous reinforcementmaterial, such as separated agglomerates or clumps of reinforcementmaterials. Aerogel blanket compositions are particularly useful forapplications requiring flexibility, since they are highly conformableand may be used like a blanket to cover surfaces of simple or complexgeometry, while also retaining the excellent thermal insulationproperties of aerogels.

Within the context of the present disclosure, the terms “flexible” and“flexibility” refer to the ability of an aerogel material or compositionto be bent or flexed without macrostructural failure. Aerogelcompositions of the present disclosure are capable of bending at least5°, at least 25°, at least 45°, at least 65°, or at least 85° withoutmacroscopic failure; and/or have a bending radius of less than 4 feet,less than 2 feet, less than 1 foot, less than 6 inches, less than 3inches, less than 2 inches, less than 1 inch, or less than ½ inchwithout macroscopic failure. Likewise, the terms “highly flexible” or“high flexibility” refer to aerogel materials or compositions capable ofbending to at least 90° and/or have a bending radius of less than ½ inchwithout macroscopic failure. Furthermore, the terms “classifiedflexible” and “classified as flexible” refer to aerogel materials orcompositions which can be classified as flexible according to ASTM C1101(ASTM International, West Conshohocken, Pa.).

Aerogel compositions of the present disclosure can be flexible, highlyflexible, and/or classified flexible. Aerogel compositions of thepresent disclosure can also be drapable. Within the context of thepresent disclosure, the terms “drapable” and “drapability” refer to theability of an aerogel material or composition to be bent or flexed to90° or more with a radius of curvature of about 4 inches or less,without macroscopic failure. Aerogel materials or compositions accordingto certain embodiments of the current invention are flexible such thatthe composition is non-rigid and may be applied and conformed tothree-dimensional surfaces or objects, or pre-formed into a variety ofshapes and configurations to simplify installation or application.

Within the context of the present disclosure, the terms “additive” or“additive element” refer to materials that may be added to an aerogelcomposition before, during, or after the production of the aerogel.Additives may be added to alter or improve desirable properties in anaerogel, or to counteract undesirable properties in an aerogel.Additives are typically added to an aerogel material either prior togelation to precursor liquid, during gelation to a transition statematerial or after gelation to a solid or semi solid material. Examplesof additives include, but are not limited to microfibers, fillers,reinforcing agents, stabilizers, thickeners, elastic compounds,opacifiers, coloring or pigmentation compounds, radiation absorbingcompounds, radiation reflecting compounds, fire-class additives,corrosion inhibitors, thermally conductive components, phase changematerials, pH adjustors, redox adjustors, HCN mitigators, off-gasmitigators, electrically conductive compounds, electrically dielectriccompounds, magnetic compounds, radar blocking components, hardeners,anti-shrinking agents, and other aerogel additives known to those in theart.

Within the context of the present disclosure, the terms “thermalconductivity” and “TC” refer to a measurement of the ability of amaterial or composition to transfer heat between two surfaces on eitherside of the material or composition, with a temperature differencebetween the two surfaces. Thermal conductivity is specifically measuredas the heat energy transferred per unit time and per unit surface area,divided by the temperature difference. It is typically recorded in SIunits as mW/m*K (milliwatts per meter*Kelvin). The thermal conductivityof a material may be determined by test methods known in the art,including, but not limited to Test Method for Steady-State ThermalTransmission Properties by Means of the Heat Flow Meter Apparatus (ASTMC518, ASTM International, West Conshohocken, Pa.); a Test Method forSteady-State Heat Flux Measurements and Thermal Transmission Propertiesby Means of the Guarded-Hot-Plate Apparatus (ASTM C177, ASTMInternational, West Conshohocken, Pa.); a Test Method for Steady-StateHeat Transfer Properties of Pipe Insulation (ASTM C335, ASTMInternational, West Conshohocken, Pa.); a Thin Heater ThermalConductivity Test (ASTM C1114, ASTM International, West Conshohocken,Pa.); Determination of thermal resistance by means of guarded hot plateand heat flow meter methods (EN 12667, British Standards Institution,United Kingdom); or Determination of steady-state thermal resistance andrelated properties—Guarded hot plate apparatus (ISO 8203, InternationalOrganization for Standardization, Switzerland). Due to different methodspossibly resulting in different results, it should be understood thatwithin the context of the present disclosure and unless expressly statedotherwise, thermal conductivity measurements are acquired according toASTM C518 standard (Test Method for Steady-State Thermal TransmissionProperties by Means of the Heat Flow Meter Apparatus), at a temperatureof about 37.5° C. at atmospheric pressure in ambient environment, andunder a compression load of about 2 psi. The measurements reported asper ASTM C518 typically correlate well with any measurements made as perEN 12667 with any relevant adjustment to the compression load. Incertain embodiments, aerogel materials or compositions of the presentdisclosure have a thermal conductivity of about 40 mW/mK or less, about30 mW/mK or less, about 25 mW/mK or less, about 20 mW/mK or less, about18 mW/mK or less, about 16 mW/mK or less, about 14 mW/mK or less, about12 mW/mK or less, about 10 mW/mK or less, about 5 mW/mK or less, or in arange between any two of these values.

Thermal conductivity measurements can also be acquired at a temperatureof about 10° C. at atmospheric pressure under compression. Thermalconductivity measurements at 10° C. are generally 0.5-0.7 mW/mK lowerthan corresponding thermal conductivity measurements at 37.5° C. Incertain embodiments, aerogel materials or compositions of the presentdisclosure have a thermal conductivity at 10° C. of about 40 mW/mK orless, about 30 mW/mK or less, about 25 mW/mK or less, about 20 mW/mK orless, about 18 mW/mK or less, about 16 mW/mK or less, about 14 mW/mK orless, about 12 mW/mK or less, about 10 mW/mK or less, about 5 mW/mK orless, or in a range between any two of these values.

Within the context of the present disclosure, the term “density” refersto a measurement of the mass per unit volume of an aerogel material orcomposition. The term “density” generally refers to the apparent densityof an aerogel material, as well as the bulk density of an aerogelcomposition. Density is typically recorded as kg/m³ or g/cc. The densityof an aerogel material or composition may be determined by methods knownin the art, including, but not limited to Standard Test Method forDimensions and Density of Preformed Block and Board—Type ThermalInsulation (ASTM C303, ASTM International, West Conshohocken, Pa.);Standard Test Methods for Thickness and Density of Blanket or BattThermal Insulations (ASTM C167, ASTM International, West Conshohocken,Pa.); Determination of the apparent density of preformed pipe insulation(EN 13470, British Standards Institution, United Kingdom); orDetermination of the apparent density of preformed pipe insulation (ISO18098, International Organization for Standardization, Switzerland). Dueto different methods possibly resulting in different results, it shouldbe understood that within the context of the present disclosure, densitymeasurements are acquired according to ASTM C167 standard (Standard TestMethods for Thickness and Density of Blanket or Batt ThermalInsulations) at 2 psi compression for thickness measurement, unlessotherwise stated. In certain embodiments, aerogel materials orcompositions of the present disclosure have a density of about 0.60 g/ccor less, about 0.50 g/cc or less, about 0.40 g/cc or less, about 0.30g/cc or less, about 0.25 g/cc or less, about 0.20 g/cc or less, about0.18 g/cc or less, about 0.16 g/cc or less, about 0.14 g/cc or less,about 0.12 g/cc or less, about 0.10 g/cc or less, about 0.05 g/cc orless, about 0.01 g/cc or less, or in a range between any two of thesevalues.

Within the context of the present disclosure, the term “hydrophobicity”refers to a measurement of the ability of an aerogel material orcomposition to repel water.

Hydrophobicity of an aerogel material or composition may be expressed interms of the liquid water uptake. Within the context of the presentdisclosure, the term “liquid water uptake” refers to a measurement ofthe potential of an aerogel material or composition to absorb orotherwise retain liquid water. Liquid water uptake can be expressed as apercent (by weight or by volume) of water that is absorbed or otherwiseretained by an aerogel material or composition when exposed to liquidwater under certain measurement conditions. The liquid water uptake ofan aerogel material or composition may be determined by methods known inthe art, including, but not limited to Standard Test Method forDetermining the Water Retention (Repellency) Characteristics of FibrousGlass Insulation (ASTM C1511, ASTM International, West Conshohocken,Pa.); Standard Test Method for Water Absorption by Immersion of ThermalInsulation Materials (ASTM C1763, ASTM International, West Conshohocken,Pa.); Thermal insulating products for building applications:Determination of short term water absorption by partial immersion (EN1609, British Standards Institution, United Kingdom). Due to differentmethods possibly resulting in different results, it should be understoodthat within the context of the present disclosure, measurements ofliquid water uptake are acquired according to ASTM C1511 standard(Standard Test Method for Determining the Water Retention (Repellency)Characteristics of Fibrous Glass Insulation), under ambient pressure andtemperature, unless otherwise stated. In certain embodiments, aerogelmaterials or compositions of the present disclosure can have a liquidwater uptake of about 50 wt % or less, about 40 wt % or less, about 30wt % or less, about 20 wt % or less, about 15 wt % or less, about 10 wt% or less, about 8 wt % or less, about 3 wt % or less, about 2 wt % orless, about 1 wt % or less, about 0.1 wt % or less, or in a rangebetween any two of these values. An aerogel material or composition thathas improved liquid water uptake relative to another aerogel material orcomposition will have a lower percentage of liquid wateruptake/retention relative to the reference aerogel materials orcompositions.

Hydrophobicity of an aerogel material or composition can be expressed interms of the water vapor uptake. Within the context of the presentdisclosure, the term “water vapor uptake” refers to a measurement of thepotential of an aerogel material or composition to absorb water vapor.Water vapor uptake can be expressed as a percent (by weight) of waterthat is absorbed or otherwise retained by an aerogel material orcomposition when exposed to water vapor under certain measurementconditions. The water vapor uptake of an aerogel material or compositionmay be determined by methods known in the art, including, but notlimited to Standard Test Method for Determining the Water Vapor Sorptionof Unfaced Mineral Fiber Insulation (ASTM C1104, ASTM International,West Conshohocken, Pa.); Thermal insulating products for buildingapplications: Determination of long term water absorption by diffusion(EN 12088, British Standards Institution, United Kingdom). Due todifferent methods possibly resulting in different results, it should beunderstood that within the context of the present disclosure,measurements of water vapor uptake are acquired according to ASTM C1104standard (Standard Test Method for Determining the Water Vapor Sorptionof Unfaced Mineral Fiber Insulation) at 49° C. and 95% humidity for 24hours (modified from 96 hours according to the ASTM C1104 standard)under ambient pressure, unless otherwise stated. In certain embodiments,aerogel materials or compositions of the present disclosure can have awater vapor uptake of about 50 wt % or less, about 40 wt % or less,about 30 wt % or less, about 20 wt % or less, about 15 wt % or less,about 10 wt % or less, about 8 wt % or less, about 3 wt % or less, about2 wt % or less, about 1 wt % or less, about 0.1 wt % or less, or in arange between any two of these values. An aerogel material orcomposition that has improved water vapor uptake relative to anotheraerogel material or composition will have a lower percentage of watervapor uptake/retention relative to the reference aerogel materials orcompositions.

Hydrophobicity of an aerogel material or composition can be expressed bymeasuring the equilibrium contact angle of a water droplet at theinterface with the surface of the material. Aerogel materials orcompositions of the present disclosure can have a water contact angle ofabout 90° or more, about 120° or more, about 130° or more, about 140° ormore, about 150° or more, about 160° or more, about 170° or more, about175° or more, or in a range between any two of these values.

Within the context of the present disclosure, the terms “heat ofcombustion”, “HOC” and “ΔH_(C)” refer to a measurement of the amount ofheat energy released in the combustion or exothermic thermaldecomposition of a material or composition. Heat of combustion istypically recorded in calories of heat energy released per gram ofaerogel material or composition (cal/g), or as megajoules of heat energyreleased per kilogram of material or composition (MJ/kg). The heat ofcombustion of a material or composition may be determined by methodsknown in the art, including, but not limited to Reaction to fire testsfor products—Determination of the gross heat of combustion (calorificvalue) (EN ISO 1716, International Organization for Standardization,Switzerland; EN adopted). Within the context of the present disclosure,heat of combustion measurements are acquired according to EN ISO 1716standards (Reaction to fire tests for products—Determination of thegross heat of combustion (calorific value)), unless otherwise stated. Incertain embodiments, aerogel compositions of the present disclosure mayhave a heat of combustion of about 750 cal/g or less, about 717 cal/g orless, about 700 cal/g or less, about 650 cal/g or less, about 600 cal/gor less, about 575 cal/g or less, about 550 cal/g or less, about 500cal/g or less, about 450 cal/g or less, about 400 cal/g or less, about350 cal/g or less, about 300 cal/g or less, about 250 cal/g or less,about 200 cal/g or less, about 150 cal/g or less, about 100 cal/g orless, about 50 cal/g or less, about 25 cal/g or less, about 10 cal/g orless, or in a range between any two of these values. An aerogelcomposition that has an improved heat of combustion relative to anotheraerogel composition will have a lower heat of combustion value, relativeto the reference aerogel compositions. In certain embodiments of thepresent disclosure, the HOC of an aerogel composite is improved byincorporating a fire-class additive into the aerogel composite.

Within the context of the present disclosure, all thermal analyses andrelated definitions are referenced with measurements performed bystarting at 25° C. and ramping at a rate of 20° C. per minute up to1000° C. in air at ambient pressure. Accordingly, any changes in theseparameters will have to be accounted for (or re-performed under theseconditions) in measuring and calculating onset of thermal decomposition,temperature of peak heat release, temperature of peak hear absorptionand the like. Within the context of the present disclosure, the terms“onset of thermal decomposition” and “T_(D)” refer to a measurement ofthe lowest temperature of environmental heat at which rapid exothermicreactions from the decomposition of organic material appear within amaterial or composition. The onset of thermal decomposition of organicmaterial within a material or composition may be measured usingthermo-gravimetric analysis (TGA). The TGA curve of a material depictsthe weight loss (% mass) of a material as it is exposed to an increasein surrounding temperature, thus indicating thermal decomposition. Theonset of thermal decomposition of a material can be correlated with theintersection point of the following tangent lines of the TGA curve: aline tangent to the base line of the TGA curve, and a line tangent tothe TGA curve at the point of maximum slope during the rapid exothermicdecomposition event related to the decomposition of organic material.Within the context of the present disclosure, measurements of the onsetof thermal decomposition of organic material are acquired using TGAanalysis as provided in this paragraph, unless otherwise stated.

The onset of thermal decomposition of a material may also be measuredusing differential scanning calorimetry (DSC) analysis. The DSC curve ofa material depicts the heat energy (mW/mg) released by a material as itis exposed to a gradual increase in surrounding temperature. The onsetof thermal decomposition temperature of a material can be correlatedwith the point in the DSC curve where the A mW/mg (change in the heatenergy output) maximally increases, thus indicating exothermic heatproduction from the aerogel material. Within the context of the presentdisclosure, measurements of onset of thermal decomposition using DSC,TGA, or both are acquired using a temperature ramp rate of 20° C./min asfurther defined in the previous paragraph, unless otherwise statedexpressly. DSC and TGA each provide similar values for this onset ofthermal decomposition, and many times, the tests are run concurrently,so that results are obtained from both. In certain embodiments, aerogelmaterials or compositions of the present disclosure have an onset ofthermal decomposition of about 300° C. or more, about 320° C. or more,about 340° C. or more, about 360° C. or more, about 380° C. or more,about 400° C. or more, about 420° C. or more, about 440° C. or more,about 460° C. or more, about 480° C. or more, about 500° C. or more,about 550° C. or more, about 600° C. or more, or in a range between anytwo of these values. Within the context herein, for example, a firstcomposition having an onset of thermal decomposition that is higher thanan onset of thermal decomposition of a second composition, would beconsidered an improvement of the first composition over the secondcomposition. It is contemplated herein that onset of thermaldecomposition of a composition or material is increased when adding oneor more fire-class additives, as compared to a composition that does notinclude any fire-class additives.

Within the context of the present disclosure, the terms “onset ofendothermic decomposition” and “TED” refer to a measurement of thelowest temperature of environmental heat at which endothermic reactionsfrom decomposition or dehydration appear within a material orcomposition. The onset of endothermic decomposition of a material orcomposition may be measured using thermo-gravimetric analysis (TGA). TheTGA curve of a material depicts the weight loss (% mass) of a materialas it is exposed to an increase in surrounding temperature. The onset ofthermal decomposition of a material may be correlated with theintersection point of the following tangent lines of the TGA curve: aline tangent to the base line of the TGA curve, and a line tangent tothe TGA curve at the point of maximum slope during the rapid endothermicdecomposition or dehydration of the material. Within the context of thepresent disclosure, measurements of the onset of endothermicdecomposition of a material or composition are acquired using TGAanalysis as provided in this paragraph, unless otherwise stated.

Within the context of the present disclosure, the terms “furnacetemperature rise” and “ΔT_(R)” refer to a measurement of the differencebetween a maximum temperature (T_(MAX)) of a material or compositionunder thermal decomposition conditions relative to a baselinetemperature of that material or composition under the thermaldecomposition conditions (usually the final temperature, or T_(FIN)).Furnace temperature rise is typically recorded in degrees Celsius, or °C. The furnace temperature rise of a material or composition may bedetermined by methods known in the art, including, but not limited toReaction to fire tests for building and transport products:Non-combustibility test (EN ISO 1182, International Organization forStandardization, Switzerland; EN adopted). Within the context of thepresent disclosure, furnace temperature rise measurements are acquiredaccording to conditions comparable to EN ISO 1182 standard (Reaction tofire tests for building and transport products: Non-combustibilitytest), unless otherwise stated. In certain embodiments, aerogelcompositions of the present disclosure can have a furnace temperaturerise of about 100° C. or less, about 90° C. or less, about 80° C. orless, about 70° C. or less, about 60° C. or less, about 50° C. or less,about 45° C. or less, about 40° C. or less, about 38° C. or less, about36° C. or less, about 34° C. or less, about 32° C. or less, about 30° C.or less, about 28° C. or less, about 26° C. or less, about 24° C. orless, or in a range between any two of these values. Within the contextof compositional stability at elevated temperatures, for example, afirst composition having a furnace temperature rise that is lower than afurnace temperature rise of a second composition, would be considered animprovement of the first composition over the second composition. It iscontemplated herein that furnace temperature rise of a composition isreduced when adding one or more fire-class additives, as compared to acomposition that does not include any fire-class additives.

Within the context of the present disclosure, the terms “flame time” and“T_(FLAME)” refer to a measurement of sustained flaming of a material orcomposition under thermal decomposition conditions, where “sustainedflaming” is a persistence of flame at any part on the visible part ofthe specimen lasting 5 seconds or longer. Flame time is typicallyrecorded in seconds or minutes. The flame time of a material orcomposition may be determined by methods known in the art, including,but not limited to Reaction to fire tests for building and transportproducts: Non-combustibility test (EN ISO 1182, InternationalOrganization for Standardization, Switzerland; EN adopted). Within thecontext of the present disclosure, flame time measurements are acquiredaccording to conditions comparable to EN ISO 1182 standard (Reaction tofire tests for building and transport products: Non-combustibilitytest), unless otherwise stated. In certain embodiments, aerogelcompositions of the present disclosure have a flame time of about 30seconds or less, about 25 seconds or less, about 20 seconds or less,about 15 seconds or less, about 10 seconds or less, about 5 seconds orless, about 2 seconds or less, or in a range between any two of thesevalues. Within the context herein, for example, a first compositionhaving a flame time that is lower than a flame time of a secondcomposition, would be considered an improvement of the first compositionover the second composition. It is contemplated herein that flame timeof a composition is reduced when adding one or more fire-classadditives, as compared to a composition that does not include anyfire-class additives.

Within the context of the present disclosure, the terms “mass loss” and“ΔM” refer to a measurement of the amount of a material, composition, orcomposite that is lost or burned off under thermal decompositionconditions. Mass loss is typically recorded as weight percent or wt %.The mass loss of a material, composition, or composite may be determinedby methods known in the art, including, but not limited to: Reaction tofire tests for building and transport products: Non-combustibility test(EN ISO 1182, International Organization for Standardization,Switzerland; EN adopted). Within the context of the present disclosure,mass loss measurements are acquired according to conditions comparableto EN ISO 1182 standard (Reaction to fire tests for building andtransport products: Non-combustibility test), unless otherwise stated.In certain embodiments, aerogel compositions of the present disclosurecan have a mass loss of about 50% or less, about 40% or less, about 30%or less, about 28% or less, about 26% or less, about 24% or less, about22% or less, about 20% or less, about 18% or less, about 16% or less, orin a range between any two of these values. Within the context herein,for example, a first composition having a mass loss that is lower than amass loss of a second composition would be considered an improvement ofthe first composition over the second composition. It is contemplatedherein that mass loss of a composition is reduced when adding one ormore fire-class additives, as compared to a composition that does notinclude any fire-class additives.

Within the context of the present disclosure, the terms “temperature ofpeak heat release” refers to a measurement of the temperature ofenvironmental heat at which exothermic heat release from decompositionis at the maximum. The temperature of peak heat release of a material orcomposition may be measured using TGA analysis, differential scanningcalorimetry (DSC) or a combination thereof. DSC and TGA each wouldprovide similar values for temperature of peak heat release, and manytimes, the tests are run concurrently, so that results are obtained fromboth. In a typical DSC analysis, heat flow is plotted against the risingtemperature and temperature of peak heat release is the temperature atwhich the highest peak in such curve occurs. Within the context of thepresent disclosure, measurements of the temperature of peak heat releaseof a material or composition are acquired using TGA analysis as providedin this paragraph, unless otherwise stated.

In the context of an endothermic material, the terms “temperature ofpeak heat absorption” refers to a measurement of the temperature ofenvironmental heat at which endothermic heat absorption fromdecomposition is at the minimum. The temperature of peak heat absorptionof a material or composition may be measured using TGA analysis,differential scanning calorimetry (DSC) or a combination thereof. In atypical DSC analysis, heat flow is plotted against the risingtemperature and temperature of peak heat absorption is the temperatureat which the lowest peak in such curve occurs. Within the context of thepresent disclosure, measurements of the temperature of peak heatabsorption of a material or composition are acquired using TGA analysisas provided in this paragraph, unless otherwise stated.

Within the context of the present disclosure, the term“low-flammability” and “low-flammable” refer to a material orcomposition which satisfy the following combination of properties: i) afurnace temperature rise of 50° C. or less; ii) a flame time of 20seconds or less; and iii) a mass loss of 50 wt % or less. Within thecontext of the present disclosure, the term “non-flammability” and“non-flammable” refer to a material or composition which satisfy thefollowing combination of properties: i) a furnace temperature rise of40° C. or less; ii) a flame time of 2 seconds or less; and iii) a massloss of 30 wt % or less. It is contemplated that flammability (e.g.,combination of furnace temperature rise, flame time, and mass loss) of acomposition is reduced upon inclusion of one or more fire-classadditives, as described herein.

Within the context of the present disclosure, the term“low-combustibility” and “low-combustible” refer to a low-flammablematerial or composition which has a total heat of combustion (HOC) lessthan or equal to 3 MJ/kg. Within the context of the present disclosure,the term “non-combustibility” and “non-combustible” refer to anon-flammable material or composition which has the heat of combustion(HOC) less than or equal to 2 MJ/kg. It is contemplated that HOC of acomposition is reduced upon inclusion of one or more fire-classadditives, as described herein.

Aerogels are described as a framework of interconnected structures thatare most commonly comprised of interconnected oligomers, polymers, orcolloidal particles. An aerogel framework may be made from a range ofprecursor materials, including inorganic precursor materials (such asprecursors used in producing silica-based aerogels); organic precursormaterials (such precursors used in producing carbon-based aerogels);hybrid inorganic/organic precursor materials; and combinations thereof.Within the context of the present disclosure, the term “amalgam aerogel”refers to an aerogel produced from a combination of two or moredifferent gel precursors; the corresponding precursors are referred toas “amalgam precursors”.

Inorganic aerogels are generally formed from metal oxide or metalalkoxide materials. The metal oxide or metal alkoxide materials may bebased on oxides or alkoxides of any metal that can form oxides. Suchmetals include, but are not limited to silicon, aluminum, titanium,zirconium, hafnium, yttrium, vanadium, cerium, and the like. Inorganicsilica aerogels are traditionally made via the hydrolysis andcondensation of silica-based alkoxides (such as tetraethoxylsilane), orvia gelation of silicic acid or water glass. Other relevant inorganicprecursor materials for silica based aerogel synthesis include, but arenot limited to metal silicates such as sodium silicate or potassiumsilicate, alkoxysilanes, partially hydrolyzed alkoxysilanes,tetraethoxylsilane (TEOS), partially hydrolyzed TEOS, condensed polymersof TEOS, tetramethoxylsilane (TMOS), partially hydrolyzed TMOS,condensed polymers of TMOS, tetra-n-propoxysilane, partially hydrolyzedand/or condensed polymers of tetra-n-propoxysilane, polyethyl silicates,partially hydrolyzed polyethysilicates, monomeric alkylalkoxy silanes,bis-trialkoxy alkyl or aryl silanes, polyhedral silsesquioxanes, orcombinations thereof.

In certain embodiments of the present disclosure, pre-hydrolyzed TEOS,such as Silbond H-5 (SBH5, Silbond Corp), which is hydrolyzed with awater/silica ratio of about 1.9-2, may be used as commercially availableor may be further hydrolyzed prior to incorporation into the gellingprocess. Partially hydrolyzed TEOS or TMOS, such as polyethysilicate(Silbond 40) or polymethylsilicate may also be used as commerciallyavailable or may be further hydrolyzed prior to incorporation into thegelling process.

Inorganic aerogels can also include gel precursors comprising at leastone hydrophobic group, such as alkyl metal alkoxides, cycloalkyl metalalkoxides, and aryl metal alkoxides, which can impart or improve certainproperties in the gel such as stability and hydrophobicity. Inorganicsilica aerogels can specifically include hydrophobic precursors such asalkylsilanes or arylsilanes. Hydrophobic gel precursors may be used asprimary precursor materials to form the framework of a gel material.However, hydrophobic gel precursors are more commonly used asco-precursors in combination with simple metal alkoxides in theformation of amalgam aerogels. Hydrophobic inorganic precursor materialsfor silica based aerogel synthesis include, but are not limited totrimethyl methoxysilane (TMS), dimethyl dimethoxysilane (DMS), methyltrimethoxysilane (MTMS), trimethyl ethoxysilane, dimethyl diethoxysilane(DMDS), methyl triethoxysilane (MTES), ethyl triethoxysilane (ETES),diethyl diethoxysilane, ethyl triethoxysilane, propyl trimethoxysilane,propyl triethoxysilane, phenyl trimethoxysilane, phenyl triethoxysilane(PhTES), hexamethyldisilazane and hexaethyldisilazane, and the like. Anyderivatives of any of the above precursors may be used and specificallycertain polymeric of other chemical groups may be added or cross-linkedto one or more of the above precursors.

Aerogels may also be treated to impart or improve hydrophobicity.Hydrophobic treatment can be applied to a sol-gel solution, a wet-gelprior to liquid extraction, or to an aerogel subsequent to liquidextraction. Hydrophobic treatment is especially common in the productionof metal oxide aerogels, such as silica aerogels. An example of ahydrophobic treatment of a gel is discussed below in greater detail,specifically in the context of treating a silica wet-gel. However, thespecific examples and illustrations provided herein are not intended tolimit the scope of the present disclosure to any specific type ofhydrophobic treatment procedure or aerogel substrate. The presentdisclosure can include any gel or aerogel known to those in the art, aswell as associated methods of hydrophobic treatment of the aerogels, ineither wet-gel form or dried aerogel form.

Hydrophobic treatment is carried out by reacting a hydroxy moiety on agel, such as a silanol group (Si—OH) present on a framework of a silicagel, with a functional group of a hydrophobizing agent. The resultingreaction converts the silanol group and the hydrophobizing agent into ahydrophobic group on the framework of the silica gel. The hydrophobizingagent compound can react with hydroxyl groups on the gel according thefollowing reaction: R_(N)MX_(4-N) (hydrophobizing agent)+MOH(silanol)→MOMR_(N) (hydrophobic group)+HX. Hydrophobic treatment cantake place both on the outer macro-surface of a silica gel, as well ason the inner-pore surfaces within the porous network of a gel.

A gel can be immersed in a mixture of a hydrophobizing agent and anoptional hydrophobic-treatment solvent in which the hydrophobizing agentis soluble, and which is also miscible with the gel solvent in thewet-gel. A wide range of hydrophobic-treatment solvents can be used,including solvents such as methanol, ethanol, isopropanol, xylene,toluene, benzene, dimethylformamide, and hexane. Hydrophobizing agentsin liquid or gaseous form may also be directly contacted with the gel toimpart hydrophobicity.

The hydrophobic treatment process can include mixing or agitation tohelp the hydrophobizing agent to permeate the wet-gel. The hydrophobictreatment process can also include varying other conditions such astemperature and pH to further enhance and optimize the treatmentreactions. After the reaction is completed, the wet-gel is washed toremove unreacted compounds and reaction by-products.

Hydrophobizing agents for hydrophobic treatment of an aerogel aregenerally compounds of the formula: R_(N)MX_(4-N); where M is the metal;R is a hydrophobic group such as CH₃, CH₂CH₃, C₆H₆, or similarhydrophobic alkyl, cycloalkyl, or aryl moieties; and X is a halogen,usually Cl. Specific examples of hydrophobizing agents include, but arenot limited to trimethylchlorosilane (TMCS), triethylchlorosilane (TECS), triphenylchlorosilane (TPCS), dimethylchlorosilane (DMCS),dimethyldichlorosilane (DMDCS), and the like. Hydrophobizing agents canalso be of the formula: Y(R₃M)₂; where M is a metal; Y is bridging groupsuch as NH or O; and R is a hydrophobic group such as CH₃, CH₂CH₃, C₆H₆,or similar hydrophobic alkyl, cycloalkyl, or aryl moieites. Specificexamples of such hydrophobizing agents include, but are not limited tohexamethyldisilazane [HMDZ] and hexamethyldisiloxane [HMDSO].Hydrophobizing agents can further include compounds of the formula:R_(N)MV_(4-N), wherein V is a reactive or leaving group other than ahalogen. Specific examples of such hydrophobizing agents include, butare not limited to vinyltriethoxysilane and vinyltrimethoxysilane.

Hydrophobic treatments of the present invention may also be performedduring the removal, exchange or drying of liquid in the gel. In aspecific embodiment, the hydrophobic treatment may be performed insupercritical fluid environment (such as, but not limited tosupercritical carbon dioxide) and may be combined with the drying orextraction step.

Within the context of the present disclosure, the term“hydrophobic-bound silicon” refers to a silicon atom within theframework of a gel or aerogel comprising at least one hydrophobic groupcovalently bonded to the silicon atom. Examples of hydrophobic-boundsilicon include, but are not limited to, silicon atoms in silica groupswithin the gel framework which are formed from gel precursors comprisingat least one hydrophobic group (such as MTES or DMDS). Hydrophobic-boundsilicon may also include, but are not limited to, silicon atoms in thegel framework or on the surface of the gel which are treated with ahydrophobizing agent (such as HMDZ) to impart or improve hydrophobicityby incorporating additional hydrophobic groups into the composition.Hydrophobic groups of the present disclosure include, but are notlimited to, methyl groups, ethyl groups, propyl groups, isopropylgroups, butyl groups, isobutyl groups, tertbutyl groups, octyl groups,phenyl groups, or other substituted or unsubstituted hydrophobic organicgroups known to those with skill in the art. Within the context of thepresent disclosure, the terms “hydrophobic group,” “hydrophobic organicmaterial,” and “hydrophobic organic content” specifically excludereadily hydrolysable organic silicon-bound alkoxy groups on theframework of the gel material, which are the product of reactionsbetween organic solvents and silanol groups. Such excluded groups aredistinguishable from hydrophobic organic content of this through NMRanalysis. The amount of hydrophobic-bound silicon contained in anaerogel can be analyzed using NMR spectroscopy, such as CP/MAS ²⁹SiSolid State NMR. An NMR analysis of an aerogel allows for thecharacterization and relative quantification of M-type hydrophobic-boundsilicon (monofunctional silica, such as TMS derivatives); D-typehydrophobic-bound silicon (bifunctional silica, such as DMDSderivatives); T-type hydrophobic-bound silicon (trifunctional silica,such as MTES derivatives); and Q-type silicon (quadfunctional silica,such as TEOS derivatives). NMR analysis can also be used to analyze thebonding chemistry of hydrophobic-bound silicon contained in an aerogelby allowing for categorization of specific types of hydrophobic-boundsilicon into sub-types (such as the categorization of T-typehydrophobic-bound silicon into T¹ species, T² species, and T³ species).Specific details related to the NMR analysis of silica materials can befound in the article “Applications of Solid-State NMR to the Study ofOrganic/Inorganic Multicomponent Materials” by Geppi et al.,specifically pages 7-9 (Appl. Spec. Rev. (2008), 44-1: 1-89), which ishereby incorporated by reference according to the specifically citedpages.

The characterization of hydrophobic-bound silicon in a CP/MAS ²⁹Si NMRanalysis can be based on the following chemical shift peaks: M¹ (30 to10 ppm); D¹ (10 to −10 ppm), D² (−10 to −20 ppm); T¹ (−30 to −40 ppm),T² (−40 to −50 ppm), T³ (−50 to −70 ppm); Q² (−70 to −85 ppm), Q³ (−85to −95 ppm), Q⁴ (−95 to −110 ppm). These chemical shift peaks areapproximate and exemplary, and are not intended to be limiting ordefinitive. The precise chemical shift peaks attributable to the varioussilicon species within a material can depend on the specific chemicalcomponents of the material, and can generally be deciphered throughroutine experimentation and analysis by those in the art.

Within the context of the present disclosure, the term “hydrophobicorganic content” or “hydrophobe content” or “hydrophobic content” refersto the amount of hydrophobic organic material bound to the framework inan aerogel material or composition. The hydrophobic organic content ofan aerogel material or composition can be expressed as a weightpercentage of the amount of hydrophobic organic material on the aerogelframework relative to the total amount of material in the aerogelmaterial or composition. Hydrophobic organic content can be calculatedby those with ordinary skill in the art based on the nature and relativeconcentrations of materials used in producing the aerogel material orcomposition. Hydrophobic organic content can also be measured usingthermo-gravimetric analysis (TGA) of the subject materials, preferablyin oxygen atmosphere (though TGA under alternate gas environments arealso useful). Specifically, the percentage of hydrophobic organicmaterial in an aerogel can be correlated with the percentage of weightloss in a hydrophobic aerogel material or composition when subjected tocombustive heat temperatures during a TGA analysis, with adjustmentsbeing made for the loss of moisture, loss of residual solvent, and theloss of readily hydrolysable alkoxy groups during the TGA analysis.Other alternative techniques such as differential scanning calorimetry,elemental analysis (particularly, carbon), chromatographic techniques,nuclear magnetic resonance spectra and other analytical techniques knownto person of skilled in the art may be used to measure and determinehydrophobe content in the aerogel compositions of the present invention.In certain instances, a combination of the known techniques may beuseful or necessary in determining the hydrophobe content of the aerogelcompositions of the present invention.

Aerogel materials or compositions of the present disclosure can have ahydrophobic organic content of 50 wt % or less, 40 wt % or less, 30 wt %or less, 25 wt % or less, 20 wt % or less, 15 wt % or less, 10 wt % orless, 8 wt % or less, 6 wt % or less, 5 wt % or less, 4 wt % or less, 3wt % or less, 2 wt % or less, 1 wt % or less, or in a range between anytwo of these values.

The term “fuel content” refers to the total amount of combustiblematerial in an aerogel material or composition, which can be correlatedwith the total percentage of weight loss in an aerogel material orcomposition when subjected to combustive heat temperatures during a TGAor TG-DSC analysis, with adjustments being made for the loss ofmoisture. The fuel content of an aerogel material or composition caninclude hydrophobic organic content, as well as other combustibleresidual alcoholic solvents, filler materials, reinforcing materials,and readily hydrolysable alkoxy groups.

Organic aerogels are generally formed from carbon-based polymericprecursors. Such polymeric materials include, but are not limited toresorcinol formaldehydes (RF), polyimide, polyacrylate, polymethylmethacrylate, acrylate oligomers, polyoxyalkylene, polyurethane,polyphenol, polybutadiane, trialkoxysilyl-terminatedpolydimethylsiloxane, polystyrene, polyacrylonitrile, polyfurfural,melamine-formaldehyde, cresol formaldehyde, phenol-furfural, polyether,polyol, polyisocyanate, polyhydroxybenze, polyvinyl alcohol dialdehyde,polycyanurates, polyacrylamides, various epoxies, agar, agarose,chitosan, and combinations thereof. As one example, organic RF aerogelsare typically made from the sol-gel polymerization of resorcinol ormelamine with formaldehyde under alkaline conditions.

Organic/inorganic hybrid aerogels are mainly comprised of (organicallymodified silica (“ormosil”) aerogels. These ormosil materials includeorganic components that are covalently bonded to a silica network.Ormosils are typically formed through the hydrolysis and condensation oforganically modified silanes, R—Si(OX)₃, with traditional alkoxideprecursors, Y(OX)₄. In these formulas, X may represent, for example,CH₃, C₂H₅, C₃H₇, C₄H₉; Y may represent, for example, Si, Ti, Zr, or Al;and R may be any organic fragment such as methyl, ethyl, propyl, butyl,isopropyl, methacrylate, acrylate, vinyl, epoxide, and the like. Theorganic components in ormosil aerogel may also be dispersed throughoutor chemically bonded to the silica network.

Within the context of the present disclosure, the term “ormosil”encompasses the foregoing materials as well as other organicallymodified materials, sometimes referred to as “ormocers.” Ormosils areoften used as coatings where an ormosil film is cast over a substratematerial through, for example, the sol-gel process. Examples of otherorganic-inorganic hybrid aerogels of the disclosure include, but are notlimited to, silica-polyether, silica-PMMA, silica-chitosan, carbides,nitrides, and other combinations of the aforementioned organic andinorganic aerogel forming compounds. Published US Pat. App. 20050192367(Paragraphs [0022]-[0038] and [0044]-[0058]) includes teachings of suchhybrid organic-inorganic materials, and is hereby incorporated byreference according to the individually cited sections and paragraphs.

In certain embodiments, aerogels of the present disclosure are inorganicsilica aerogels formed primarily from prepolymerized silica precursorspreferably as oligomers, or hydrolyzed silicate esters formed fromsilicon alkoxides in an alcohol solvent. In certain embodiments, suchprepolymerized silica precursors or hydrolyzed silicate esters may beformed in situ from other precurosrs or silicate esters such as alkoxysilanes or water glass. However, the disclosure as a whole may bepracticed with any other aerogel compositions known to those in the art,and is not limited to any one precursor material or amalgam mixture ofprecursor materials.

Production of an aerogel generally includes the following steps: i)formation of a sol-gel solution; ii) formation of a gel from the sol-gelsolution; and iii) extracting the solvent from the gel materials throughinnovative processing and extraction, to obtain a dried aerogelmaterial. This process is discussed below in greater detail,specifically in the context of forming inorganic aerogels such as silicaaerogels. However, the specific examples and illustrations providedherein are not intended to limit the present disclosure to any specifictype of aerogel and/or method of preparation. The present disclosure caninclude any aerogel formed by any associated method of preparation knownto those in the art, unless otherwise noted.

The first step in forming an inorganic aerogel is generally theformation of a sol-gel solution through hydrolysis and condensation ofsilica precursors, such as, but not limited to, metal alkoxideprecursors in an alcohol-based solvent. Major variables in the formationof inorganic aerogels include the type of alkoxide precursors includedin the sol-gel solution, the nature of the solvent, the processingtemperature and pH of the sol-gel solution (which may be altered byaddition of an acid or a base), and precursor/solvent/water ratio withinthe sol-gel solution. Control of these variables in forming a sol-gelsolution can permit control of the growth and aggregation of the gelframework during the subsequent transition of the gel material from the“sol” state to the “gel” state. While properties of the resultingaerogels are affected by the pH of the precursor solution and the molarratio of the reactants, any pH and any molar ratios that permit theformation of gels may be used in the present disclosure.

A sol-gel solution is formed by combining at least one gelling precursorwith a solvent. Suitable solvents for use in forming a sol-gel solutioninclude lower alcohols with 1 to 6 carbon atoms, particularly 2 to 4,although other solvents can be used as known to those with skill in theart. Examples of useful solvents include, but are not limited tomethanol, ethanol, isopropanol, ethyl acetate, ethyl acetoacetate,acetone, dichloromethane, tetrahydrofuran, and the like. Multiplesolvents can also be combined to achieve a desired level of dispersionor to optimize properties of the gel material. Selection of optimalsolvents for the sol-gel and gel formation steps thus depends on thespecific precursors, fillers, and additives being incorporated into thesol-gel solution; as well as the target processing conditions forgelling and liquid extraction, and the desired properties of the finalaerogel materials.

Water can also be present in the precursor-solvent solution. The wateracts to hydrolyze the metal alkoxide precursors into metal hydroxideprecursors. The hydrolysis reaction can be (using TEOS in ethanolsolvent as an example): Si(OC₂H₅)₄+4H₂O→Si(OH)₄+4(C₂H₅OH). The resultinghydrolyzed metal hydroxide precursors remain suspended in the solventsolution in a “sol” state, either as individual molecules or as smallpolymerized (or oligomarized) colloidal clusters of molecules. Forexample, polymerization/condensation of the Si(OH)₄ precursors can occuras follows: 2 Si(OH)₄═(OH)₃Si—O—Si(OH)₃+H₂O. This polymerization cancontinue until colloidal clusters of polymerized (or oligomarized) SiO₂(silica) molecules are formed.

Acids and bases can be incorporated into the sol-gel solution to controlthe pH of the solution, and to catalyze the hydrolysis and condensationreactions of the precursor materials. While any acid may be used tocatalyze precursor reactions and to obtain a lower pH solution,exemplary acids include HCl, H₂SO₄, H₃PO₄, oxalic acid and acetic acid.Any base may likewise be used to catalyze precursor reactions and toobtain a higher pH solution, with an exemplary base comprising NH₄OH.

The sol-gel solution can include additional co-gelling precursors, aswell as filler materials and other additives. Filler materials and otheradditives may be dispensed in the sol-gel solution at any point beforeor during the formation of a gel. Filler materials and other additivesmay also be incorporated into the gel material after gelation throughvarious techniques known to those in the art. In certain embodiments,the sol-gel solution comprising the gelling precursors, solvents,catalysts, water, filler materials, and other additives is a homogenoussolution that is capable of effective gel formation under suitableconditions.

Once a sol-gel solution has been formed and optimized, the gel-formingcomponents in the sol-gel can be transitioned into a gel material. Theprocess of transitioning gel-forming components into a gel materialcomprises an initial gel formation step wherein the gel solidifies up tothe gel point of the gel material. The gel point of a gel material maybe viewed as the point where the gelling solution exhibits resistance toflow and/or forms a substantially continuous polymeric frameworkthroughout its volume. A range of gel-forming techniques is known tothose in the art. Examples include, but are not limited to maintainingthe mixture in a quiescent state for a sufficient period of time;adjusting the pH of the solution; adjusting the temperature of thesolution; directing a form of energy onto the mixture (ultraviolet,visible, infrared, microwave, ultrasound, particle radiation,electromagnetic); or a combination thereof.

The process of transitioning gel-forming components (gel precursors)into a gel material may also include an aging step (also referred to ascuring) prior to liquid extraction or removal of the solvent from thegel (also referred to as drying of the gel). Aging a gel material afterit reaches its gel point can further strengthen the gel framework byincreasing the number of cross-linkages within the network. The durationof gel aging can be adjusted to control various properties within theresulting aerogel material. This aging procedure can be useful inpreventing potential volume loss and shrinkage during liquid extraction.Aging can involve maintaining the gel (prior to extraction) at aquiescent state for an extended period, maintaining the gel at elevatedtemperatures, adding cross-linkage promoting compounds, or anycombination thereof. Preferred temperatures for aging are typicallybetween about 10° C. and about 100° C., though other suitabletemperatures are contemplated herein as well. The aging of a gelmaterial typically continues up to the liquid extraction of the wet-gelmaterial.

The time period for transitioning gel-forming materials (gel precursors)into a gel material includes both the duration of the initial gelformation (from initiation of gelation up to the gel point), as well asthe duration of any subsequent curing and aging of the gel materialprior to liquid extraction or removal of the solvent from the gel (alsoreferred to as drying of the gel) (from the gel point up to theinitiation of liquidextraction/removal of solvent). The total timeperiod for transitioning gel-forming materials into a gel material istypically between about 1 minute and several days, typically about 30hours or less, about 24 hours or less, about 15 hours or less, about 10hours or less, about 6 hours or less, about 4 hours or less, about 2hours or less, and preferably, about 1 hour or less, about 30 minutes orless, about 15 minutes or less, or about 10 minutes or less.

In another embodiment, the resulting gel material may be washed in asuitable secondary solvent to replace the primary reaction solventpresent in the wet-gel. Such secondary solvents may be linear monohydricalcohols with one or more aliphatic carbon atoms, dihydric alcohols with2 or more carbon atoms, branched alcohols, cyclic alcohols, alicyclicalcohols, aromatic alcohols, polyhydric alcohols, ethers, ketones,cyclic ethers or their derivative. In another embodiment, the resultinggel material may be washed in additional quantities of the same solventpresent within the gel material, which among others, may remove anyundesired by-products or other precipitates in the gel material.

Once a gel material has been formed and processed, the liquid of the gelcan then be at least partially extracted from the wet-gel usingextraction methods, including innovative processing and extractiontechniques, to form an aerogel material. Liquid extraction, among otherfactors, plays an important role in engineering the characteristics ofaerogels, such as porosity and density, as well as related propertiessuch as thermal conductivity. Generally, aerogels are obtained when aliquid is extracted from a gel in a manner that causes low shrinkage tothe porous network and framework of the wet gel. This liquid extractionmay also be referred to as solvent removal or drying among others.

One example of an alternative method of forming a silica aerogel usesmetal oxide salts such as sodium silicate, also known as water glass. Awater glass solution is first produced by mixing sodium silicate withwater and an acid to form a silicic acid precursor solution. Saltby-products may be removed from the silicic acid precursor by ionexchange, surfactant separation, membrane filtration, or other chemicalor physical separation techniques. The resulting sol can then be gelled,such as by the addition of a base catalyst, to produce a hydrogel. Thehydrogel can be washed to remove any residual salts or reactants.Removing the water from the pores of the gel can then be performed viaexchange with a polar organic solvent such as ethanol, methanol, oracetone. The liquid in the gel is then at least partially extractedusing innovative processing and extraction techniques. In an embodiment,

Aerogels are commonly formed by removing the liquid mobile phase fromthe gel material at a temperature and pressure near or above thecritical point of the liquid mobile phase. Once the critical point isreached (near critical) or surpassed (supercritical) (i.e., pressure andtemperature of the system is at or higher than the critical pressure andcritical temperature respectively) a new supercritical phase appears inthe fluid that is distinct from the liquid or vapor phase. The solventcan then be removed without introducing a liquid-vapor interface,capillary pressure, or any associated mass transfer limitationstypically associated with liquid-vapor boundaries. Additionally, thesupercritical phase is more miscible with organic solvents in general,thus having the capacity for better extraction. Co-solvents and solventexchanges are also commonly used to optimize the supercritical fluiddrying process.

If evaporation or extraction occurs well below the critical point,capillary forces generated by liquid evaporation can cause shrinkage andpore collapse within the gel material. Maintaining the mobile phase nearor above the critical pressure and temperature during the solventextraction process reduces the negative effects of such capillaryforces. In certain embodiments of the present disclosure, the use ofnear-critical conditions just below the critical point of the solventsystem may allow production of aerogel materials or compositions withsufficiently low shrinkage, thus producing a commercially viableend-product.

Several additional aerogel extraction techniques are known in the art,including a range of different approaches in the use of supercriticalfluids in drying aerogels. For example, Kistler (J. Phys. Chem. (1932)36: 52-64) describes a simple supercritical extraction process where thegel solvent is maintained above its critical pressure and temperature,thereby reducing evaporative capillary forces and maintaining thestructural integrity of the gel network. U.S. Pat. No. 4,610,863describes an extraction process where the gel solvent is exchanged withliquid carbon dioxide and subsequently extracted at conditions wherecarbon dioxide is in a supercritical state. U.S. Pat. No. 6,670,402teaches extracting a liquid from a gel via rapid solvent exchange byinjecting supercritical (rather than liquid) carbon dioxide into anextractor that has been pre-heated and pre-pressurized to substantiallysupercritical conditions or above, thereby producing aerogels. U.S. Pat.No. 5,962,539 describes a process for obtaining an aerogel from apolymeric material that is in the form a sol-gel in an organic solvent,by exchanging the organic solvent for a fluid having a criticaltemperature below a temperature of polymer decomposition, and extractingthe fluid/sol-gel using a supercritical fluid such as supercriticalcarbon dioxide, supercritical ethanol, or supercritical hexane. U.S.Pat. No. 6,315,971 discloses a process for producing gel compositionscomprising drying a wet gel comprising gel solids and a drying agent toremove the drying agent under drying conditions sufficient to reduceshrinkage of the gel during drying. U.S. Pat. No. 5,420,168 describes aprocess whereby Resorcinol/Formaldehyde aerogels can be manufacturedusing a simple air-drying procedure. U.S. Pat. No. 5,565,142 describesdrying techniques in which the gel surface is modified to be strongerand more hydrophobic, such that the gel framework and pores can resistcollapse during ambient drying or subcritical extraction. Other examplesof extracting a liquid from aerogel materials can be found in U.S. Pat.Nos. 5,275,796 and 5,395,805.

One embodiment of extracting a liquid from the wet-gel usessupercritical fluids such as carbon dioxide, including, for examplefirst substantially exchanging the primary solvent present in the porenetwork of the gel with liquid carbon dioxide; and then heating the wetgel (typically in an autoclave) beyond the critical temperature ofcarbon dioxide (about 31.06° C.) and increasing the pressure of thesystem to a pressure greater than the critical pressure of carbondioxide (about 1070 psig). The pressure around the gel material can beslightly fluctuated to facilitate removal of the liquid from the gel.Carbon dioxide can be recirculated through the extraction system tofacilitate the continual removal of the primary solvent from the wetgel. Finally, the temperature and pressure are slowly returned toambient conditions to produce a dry aerogel material. Carbon dioxide canalso be pre-processed into a supercritical state prior to being injectedinto an extraction chamber.

Another example of an alternative method of forming aerogels includesreducing the damaging capillary pressure forces at the solvent/poreinterface by chemical modification of the matrix materials in their wetgel state via conversion of surface hydroxyl groups to hydrophobictrimethylsilylethers, thereby allowing for liquid extraction from thegel materials at temperatures and pressures below the critical point ofthe solvent.

In yet another embodiment, liquid (solvent) in the gel material may befrozen at lower temperatures followed by a sublimation process wherebythe solvent is removed from the gel material. Such removal or drying ofthe solvent from the gel material is understood to be within the scopeof this disclosure. Such removal largely preserves the gel structure,thus producing an aerogel with unique properties.

Large-scale production of aerogel materials or compositions can becomplicated by difficulties related to the continuous formation of gelmaterials on a large scale; as well as the difficulties related toliquid extraction from gel materials in large volumes using innovativeprocessing and extraction techniques. In certain embodiments, aerogelmaterials or compositions of the present disclosure are accommodating toproduction on a large scale. In certain embodiments, gel materials ofthe present disclosure can be produced in large scale through acontinuous casting and gelation process. In certain embodiments, aerogelmaterials or compositions of the present disclosure are produced in alarge scale, requiring the use of large-scale extraction vessels. Largescale extraction vessels of the present disclosure can includeextraction vessels which have a volume of about 0.1 m³ or more, about0.25 m³ or more, about 0.5 m³ or more, or about 0.75 m³ or more.

Aerogel compositions of the present disclosure can have a thickness of15 mm or less, 10 mm or less, 5 mm or less, 3 mm or less, 2 mm or less,or 1 mm or less.

Aerogel compositions may be reinforced with various reinforcementmaterials to achieve a more flexible, resilient and conformablecomposite product. The reinforcement materials can be added to the gelsat any point in the gelling process to produce a wet, reinforced gelcomposition. The wet gel composition may then be dried to produce areinforced aerogel composition.

Aerogel compositions may be OCMF-reinforced with various open-celledmacroporous framework reinforcement materials to achieve a moreflexible, resilient and conformable composite product. The OCMFreinforcement materials can be added to the gels at any point in thegelling process before gelation to produce a wet, reinforced gelcomposition. The wet gel composition may then be dried to produce anOCMF-reinforced aerogel composition. OCMF reinforcement materials can beformed from organic polymeric materials such as melamine or melaminederivatives, and are present in the form of a continuous sheet or panel.

Melamine OCMF materials can be produced from melamine-formaldehydeprecondensation solution. An aqueous solution of a melamine-formaldehydecondensation product is produced by combining a melamine-formaldehydeprecondensate with a solvent, an emulsifier/dispersant, a curing agentsuch as an acid, and a blowing agent such as a C5 to C7 hydrocarbon. Themelamine-formaldehyde solution or resin is then cured at elevatedtemperature above the boiling point of the blowing agent to produce anOCMF comprising a multiplicity of interconnected, three-dimensionallybranched melamine structures, with a corresponding network ofinterconnected pores integrated within the framework. Themelamine-formaldehyde precondensates generally have a molar ratio offormaldehyde to melamine in the range from 5:1 to 1.3:1 and typically inthe range from 3.5:1 to 1.5:1. The precondensates can be in the form ofa powder, a spray, a resin, or a solution. The solvent included in themelamine-formaldehyde precondensation solution can comprise alcoholssuch as methanol, ethanol, or butanol.

The emulsifier/dispersant included in the melamine-formaldehydeprecondensation solution can comprise an anionic surfactant, a cationicemulsifier, or a nonionic surfactant. Useful anionic surfactantsinclude, but are not limited to diphenylene oxide sulfonates, alkane-and alkylbenzenesulfonates, alkylnaphthalenesulfonates,olefinsulfonates, alkyl ether sulfonates, fatty alcohol sulfates, ethersulfates, α-sulfo fatty acid esters, acylaminoalkanesulfonates, acylisethionates, alkyl ether carboxylates, N-acylsarcosinates, alkyl, andalkylether phosphates. Useful cationic emulsifiers include, but are notlimited to alkyltriammonium salts, alkylbenzyl dimethylammonium salts,or alkylpyridinium salts. Useful nonionic surfactants include, but arenot limited to alkylphenol polyglycol ethers, fatty alcohol polyglycolethers, fatty acid polyglycol ethers, fatty acid alkanolamides, ethyleneoxide-propylene oxide block copolymers, amine oxides, glycerol fattyacid esters, sorbitan esters, and alkylpolyglycosides. Theemulsifier/dispersant can be added in amounts from 0.2% to 5% by weight,based on the melamine-formaldehyde precondensate.

The curing agent included in the melamine-formaldehyde precondensationsolution can comprise acidic compounds. The amount of these curatives isgenerally in the range from 0.01% to 20% by weight and typically in therange from 0.05% to 5% by weight, all based on the melamine-formaldehydeprecondensate. Useful acidic compounds include, but are not limited toorganic and inorganic acids, for example selected from the groupconsisting of hydrochloric acid, sulfuric acid, phosphoric acid, nitricacid, formic acid, acetic acid, oxalic acid, toluenesulfonic acids,amidosulfonic acids, acid anhydrides, and mixtures thereof.

The blowing agent included in the melamine-formaldehyde precondensationsolution can comprise physical blowing agents or chemical blowingagents. Useful physical blowing agents include, but are not limited tohydrocarbons, such as pentane and hexane; halogenated hydrocarbons, moreparticularly chlorinated and/or fluorinated hydrocarbons, for examplemethylene chloride, chloroform, trichloroethane, chlorofluorocarbons,and hydro-chlorofluorocarbons (HCFCs); alcohols, for example methanol,ethanol, n-propanol or isopropanol; ethers, ketones and esters, forexample methyl formate, ethyl formate, methyl acetate or ethyl acetate;and gases, such as air, nitrogen or carbon dioxide. In certainembodiments, it is preferable to add a physical blowing agent having aboiling point between 0° C. and 80° C. Useful chemical blowing agentsinclude, but are not limited to, isocyanates mixed with water (releasingcarbon dioxide as active blowing agent); carbonates and/or bicarbonatesmixed with acids (releasing carbon dioxide as active blowing agent); andazo compounds, for example azodicarbonamide. The blowing agent ispresent in the melamine-formaldehyde precondensation solution in anamount of 0.5% to 60% by weight, particularly 1% to 40% by weight and incertain embodiments 1.5% to 30% by weight, based on themelamine-formaldehyde precondensate.

The melamine-formaldehyde precondensation solution can be formed into amelamine OCMF material by heating the solution to a temperaturegenerally above the boiling point of the blowing agent used, therebyforming an OCMF comprising a multiplicity of interconnected,three-dimensionally branched melamine structures, with a correspondingnetwork of interconnected open-cell pores integrated within theframework. The introduction of heat energy may be effected viaelectromagnetic radiation, for example via high-frequency radiation at 5to 400 kW, for example 5 to 200 kW and in certain embodiments 9 to 120kW per kilogram of the mixture used in a frequency range from 0.2 to 100GHz, or more specifically 0.5 to 10 GHz. Magnetrons are a useful sourceof dielectric radiation, and one magnetron can be used or two or moremagnetrons at the same time.

The OCMF material can be dried to remove residual liquids (water,solvent, blowing agent) from the OCMF material. An after-treatment canalso be utilized to hydrophobicize the OCMF material. Thisafter-treatment can employ hydrophobic coating agents having highthermal stability and/or low flammability, for example silicones,siliconates or fluorinated compounds.

The density of the melamine OCMF is generally in the range from 0.005 to0.3 g/cc, for example in the range from 0.01 to 0.2 g/cc, in certainembodiments in the range from 0.03 to 0.15 g/cc, or most specifically inthe range from 0.05 to 0.15 g/cc. The average pore diameter of themelamine OCMF is generally in the range of 10 μm to about 1000 μm,particularly in the range from 50 to 700 μm.

In an embodiment, OCMF reinforcement materials are incorporated into theaerogel composition as continuous sheet. The process comprises initiallyproducing a continuous sheet of OCMF-reinforced gel by casting orimpregnating a gel precursor solution into a continuous sheet of OCMFreinforcement material, and allowing the material to form into areinforced gel composite sheet. The liquid may then be at leastpartially extracted from the OCMF-reinforced gel composite sheet toproduce a sheet-like, OCMF-reinforced aerogel composition.

Aerogel compositions can include an opacifier to reduce the radiativecomponent of heat transfer. At any point prior to gel formation,opacifying compounds or precursors thereof may be dispersed into themixture comprising gel precursors. Examples of opacifying compoundsinclude, but are not limited to Boron Carbide (B₄C), Diatomite,Manganese ferrite, MnO, NiO, SnO, Ag₂O, Bi₂O₃, carbon black, titaniumoxide, iron titanium oxide, aluminum oxide, zirconium silicate,zirconium oxide, iron (II) oxide, iron (III) oxide, manganese dioxide,iron titanium oxide (ilmenite), chromium oxide, carbides (such as SiC,TiC or WC), or mixtures thereof. Examples of opacifying compoundprecursors include, but are not limited to TiOSO₄ or TiOCl₂.

Aerogel compositions can include one or more fire-class additive. Withinthe context of the present disclosure, the term “fire-class additive”refers to a material that has an endothermic effect in the context ofreaction to fire and can be incorporated into an aerogel composition.Furthermore, in certain embodiments, fire-class additives have an onsetof endothermic decomposition (ED) that is no more than 100° C. greaterthan the onset of thermal decomposition (T_(d)) of the aerogelcomposition in which the fire-class additive is present, and in certainembodiments, also an ED that is no more than 50° C. lower than the T_(d)of the aerogel composition in which the fire-class additive is present.In other words, the ED of fire-class additives has a range of (T_(d)−50°C.) to (T_(d)+100° C.):

$E_{D}\left\{ \begin{matrix}{{\max:T_{d}} + {100{{^\circ}C}}} \\{{\min:T_{d}} - {50{{^\circ}C}}}\end{matrix} \right.$

Prior to, concurrent with, or even subsequent to incorporation or mixingwith the sol (e.g., silica sol prepared from alkyl silicates or waterglass in various ways as understood in prior art), fire-class additivescan be mixed with or otherwise dispersed into a medium including ethanoland optionally up to 10% vol. water. The mixture may be mixed and/oragitated as necessary to achieve a substantially uniform dispersion ofadditives in the medium. Without being bound by theory, utilizing ahydrated form of the above-referenced clays and other fire-classadditives provides an additional endothermic effect. For example,halloysite clay (commercially available under the tradename DRAGONITEfrom Applied Minerals, Inc. or from Imerys simply as Halloysite),kaolinite clay are aluminum silicate clays that in hydrated form has anendothermic effect by releasing water of hydration at elevatedtemperatures (gas dilution). As another example, carbonates in hydratedform can release carbon dioxide on heating or at elevated temperatures.

Within the context of the present disclosure, the terms “heat ofdehydration” means the amount of heat required to vaporize the water(and dihydroxylation, if applicable) from the material that is inhydrated form when not exposed to elevated temperatures. Heat ofdehydration is typically expressed on a unit weight basis.

In certain embodiments, fire-class additives of the present disclosurehave an onset of thermal decomposition of about 350° C. or more, about400° C. or more, about 450° C. or more, about 500° C. or more, about550° C. or more, about 600° C. or more, about 650° C. or more, about700° C. or more, about 750° C. or more, about 800° C. or more, or in arange between any two of these values. In certain embodiments,fire-class additives of the present disclosure have an onset of thermaldecomposition of about 440° C. or 570° C. In certain embodiments,fire-class additives of the present disclosure have an onset of thermaldecomposition which is no more than 50° C. more or less than the Et ofthe aerogel composition (without the fire-class additive) into which thefire-class additive is incorporated, no more than 40° C. more or less,no more than 30° C. more or less, no more than 20° C. more or less, nomore than 10° C. more or less, no more than 5° C. more or less, or in arange between any two of these values

The fire-class additives of this disclosure include, clay materials suchas, but not limited to, phyllosilicate clays (such as illite), kaolinite(aluminum silicate; Al₂Si₂O₅(OH)₄), halloysite (aluminum silicate;Al₂Si₂O₅(OH)₄)), endellite (aluminum silicate; Al₂Si₂O₅(OH)₄), mica(silica minerals), diaspore, gibbsite (aluminum hydroxide),montmorillonite, beidellite, pyrophyllite (aluminum silicate;Al₂Si₄O₁₀(OH)₂), nontronite, bravaisite, smectite, leverrierite,rectorite, celadonite, attapulgite, chloropal, volkonskoite, allophane,racewinite, dillnite, severite, miloschite, collyrite, cimolite andnewtonite, magnesium hydroxide (or magnesium dihydroxide, “MDH”),alumina trihydrate (“ATH”), carbonates such as, but not limited to,dolomite and lithium carbonate. Among the clay materials, certainembodiments of the present disclosure use clay materials that have atleast a partial layered structure. In certain embodiments of the presentdisclosure, clay materials as fire-class additives in the aerogelcompositions have at least some water such as in hydrated form. Theadditives may be in hydrated crystalline form or may become hydrated inthe manufacturing/processing of the compositions of the presentinvention. In certain embodiments, fire-class additive also include lowmelting additives that absorb heat without a change in chemicalcomposition. An example of this class is a low melting glass, such asinert glass beads. Other additives that may be useful in thecompositions of the present disclosure include, but are not limited to,wollastonite (calcium silicate) and titanium dioxide (TiO₂). In certainembodiments, other additives may include infrared opacifiers such as,but not limited to, titanium dioxide or silicon carbide, ceramifierssuch as, but not limited to, low melting glass frit, calcium silicate orcharformers such as, but not limited to, phosphates and sulfates. Incertain embodiments, additives may require special processingconsiderations such as techniques to ensure the additives are uniformlydistributed and not agglomerated heavily to cause product performancevariations. The processing techniques may involve additional static anddynamic mixers, stabilizers, adjustment of process conditions and othersknown in the art. The amount of additives in the final aerogelcompositions may depend on various other property requirements and mayvary from 5% to about 70% by weight. In certain embodiments, the amountof additives in the final aerogel composition is between 10 and 60 wt %and in certain preferred embodiments, it is between 20 and 40 wt %. Incertain embodiments, the additives may be of more than one type. One ormore fire-class additives may also be present in the final aerogelcompositions. In certain preferred embodiments which include aluminumsilicate fire-class additives, the additives are present in the finalaerogel compositions in about 60-70 wt %.

In certain embodiments of the present disclosure, methods are providedto prepare OCMF reinforced aerogel compositions with fire-classperformance. The fire-class compositions of these embodiments alsopossess hydrophobicity sufficient for use as thermal insulation inindustrial environments, as measured by water uptake and low thermalconductivity to help meet the ever-demanding energy conservation needs.To obtain these combinations of desirable properties, simply loadingadditives or even fire-class additives are not successful. While one cantry various permutations and combinations or various additives andarrive at an optimized solution, such efforts are not always successfuland present risks for a viable manufacturing with repeatable qualitycontrol on these desired properties. An important aspect of theseembodiments is to assess the thermal behavior (assessed throughthermogravimetry or differential scanning calorimetry) of thecomposition that would otherwise provide all desirable properties exceptfor the fire performance and consider a fire-class additive that closelymatches the onset of thermal decomposition of the underlying compositionor alternatively, the temperature at which most heat is emitted with thefire-class additives' onset of thermal decomposition or the temperatureat which most heat is absorbed.

In certain embodiments, the desired fire properties of the finalcomposition may include not just the inherent property such as heat ofcombustion (ISO 1716), but also system fire properties such as reactionto fire performance as per ISO 1182. In the case of ISO 1182, weightloss, increase in furnace temperature, and flame time are assessed whenexposed to a furnace at a temperature of about 750° C.

An OCMF reinforced aerogel composition may have various components thatadd fuel to the system. Additionally, it may have various othercomponents, while not contributing as fuel, may interfere in combustionupon exposure to fire. As such, combustion behavior of such systemscannot be predicted simply based on the constituent elements. Insituations where a multitude of properties are desired, in certainembodiments, the composition should be arrived at without regard to itsfire property and such arrived composition's thermal performance shouldbe assessed to find a suitable fire-class additive that will provide thefire property without compromising the other properties the startingcomposition was intended to provide.

In certain embodiments, onset of thermal decomposition is a criticalproperty of the composition. In certain other embodiments, thetemperature at which the peak heat release may be a critical propertyfor the purposes of developing an enhanced fire-performing aerogel OCMFcompositions. When multiple fuel components are present in thecomposition identified by multiple peaks in the DSC curve, suchcompositions are well served by matching the temperature of the peakheat release of the OCMF reinforced aerogel composition with afire-class additive having a temperature of endothermic peak heatrelease within 140° C., 120° C., 100° C. or 80° C. In many embodiments,the temperature of endothermic peak heat release is within 50° C.

The aerogel materials and compositions of the present disclosure havebeen shown to be highly effective as insulation materials. However,application of the methods and materials of the present disclosure arenot intended to be limited to applications related to insulation. Themethods and materials of the present disclosure can be applied to anysystem or application, which would benefit from the unique combinationof properties or procedures provided by the materials and methods of thepresent disclosure.

EXAMPLES

The following examples provide various non-limiting embodiments andproperties of the present disclosure. In the examples below, theadditive wt % is provided with 100% reference being the weight of thesilica and hydrophobe constituents of the aerogel composition. Thethermal analyses, TGA and DSC were performed using Netzsch STA449 F1Jupitor simultaneous thermal analyzer starting at 25° C. and ramping ata rate of 20° C. per minute up to 1000° C. in air at ambient pressure.Any reference to sol hydrophobe content refers to weight of solidmaterials in the final aerogel composition derived from hydrophobicalkyl silanes in the sols as a percentage of the weight of the finalaerogel composition.

Example 1

Polyethylsilicate sol was produced by hydrolyzing TEOS(tetraethoxysilane) in ethanol and water with sulfuric acid catalyst,and was then stirred at ambient temperature for about 16 h.Polymethylsilsesquioxane sol as produced by hydrolyzing MTES (methyltriethoxy silane) and DIVIDES (dimethyl diethoxy silane) (about 4:1molar ratio) in ethanol and water with phosphoric acid catalyst, and wasthen stirred at ambient temperature for no less than 16 hours. Thepolyethylsilicate and polymethylsilsesquioxane (MTES+DMDES) sols werecombined (about 2:1 weight ratio) to form a precursor sol which targeted30-40 wt % of total hydrophobe content in the final aerogel compositionprepared from the sol. The combined precursor sol was stirred at ambienttemperature for no less than 2 hours.

Example 2

A sample of melamine OCMF material (BASOTECT UF from BASF) measuring 10mm thick with a density of approximately 6 kg/m³ was provided. Asubstantially uniform mixture of 70 g of magnesium dihydroxide(fire-class additive; MDH) in about 450 mL of ethanol (with up to 10%vol. water) was combined with about 540 mL of silica sol from Example 1,and stirred for no less than 5 minutes. About 10 mL of 28 wt % NH₄OHsolution was then added, followed by at least 1 minute of stirring thesol mixture. The sol mixture was then infiltrated into the melamine OCMFmaterial and allowed to gel, with gelation occurring within 2 minutes.The resulting gel composition was allowed to sit and cure forapproximately 10 minutes. The gel composition was then aged for 16 hoursat 68° C. in ethanol aging fluid containing 10 vol % H₂O and 1.1 wt/vol% NH₄OH (1.1 g of NH₄OH per 100 mL of fluid) at a fluid to gelcomposition ratio of about 1.5:1. Aging temperature and aging fluidcomposition may be further varied to change the overall ageing time.

The gel composition coupons (samples) where then subjected to solventextraction by way of supercritical CO₂ and then dried at 120° C. for 4hours. Target silica density was 0.07 g/cc, and the resulting materialdensity of the aerogel composite was 0.159 g/cc. The hydrophobe contentof the aerogel composition was about 4.34 wt %.

Example 3

A gel composition was produced using the same procedure as Example 2,except a mixture of 72 g of MDH in about 529 mL of ethanol (with up to10% vol. water) was combined with about 460 mL of silica sol fromExample 1. Target silica density was 0.06 g/cc, and the resultingmaterial density of the aerogel composition was 0.185 g/cc. Thehydrophobe content of the aerogel composition was about 3.97 wt %.

Example 4

A gel composition was produced using the same procedure as Example 2,except a substantially uniform mixture of 96 g of MDH in about 376 mL ofethanol (with up to 10% vol. water) was combined with about 614 mL ofsilica sol from Example 1. Target silica density was 0.08 g/cc, and theresulting material density of the aerogel composition was 0.178 g/cc.The hydrophobe content of the aerogel composition was about 3.97 wt %.

Example 5

A gel composition was produced using the same procedure as Example 2,except a substantially uniform mixture of 84 g of MDH in about 539 mL ofethanol (with up to 10% vol. water) was combined with about 460 mL ofsilica sol from Example 1. Target silica density was 0.06 g/cc, and theresulting material density of the aerogel composition was 0.142 g/cc.The hydrophobe content of the aerogel composition was about 3.6 wt %.

Example 6

A gel composition was produced using the same procedure as Example 2,except a substantially uniform mixture of about 529 mL of ethanol (withup to 10% vol. water; no fire-class additives) was combined with about460 mL of silica sol from Example 1. Target silica density was 0.06g/cc, and the resulting material density of the aerogel composition was0.074 g/cc. The hydrophobe content of the aerogel composition was about8.3 wt %.

Example 7

A gel composition was produced using the same procedure as Example 2,except a substantially uniform mixture of 72 g of inert glass beads(fire-class additive) in about 529 mL of ethanol (with up to 10% vol.water) was combined with about 460 mL of silica sol from Example 1.Target silica density was 0.06 g/cc, and the resulting material densityof the aerogel composition was 0.141 g/cc. The hydrophobe content of theaerogel composition was about 3.93 wt %.

Example 8

A gel composition was produced using the same procedure as Example 2,except a substantially uniform mixture of 60 g of wollastonite(commercially available as NYAD) in about 529 mL of ethanol solvent wascombined with about 460 mL of silica sol from Example 1. Target silicadensity was 0.06 g/cc, and the resulting material density of the aerogelcomposition was 0.161 g/cc. The hydrophobe content of the aerogelcomposition was about 3.95 wt %.

Example 9

A gel composition was produced using the same procedure as Example 2,except a substantially uniform mixture of 72 g of titanium dioxide(fire-class additive; TiO₂) in about 529 mL of ethanol (with up to 10%vol. water) was combined with about 460 mL of silica sol from Example 1.Target silica density was 0.06 g/cc, and the resulting material densityof the aerogel composition was 0.159 g/cc. The hydrophobe content of theaerogel composition was about 3.95 wt %.

Example 10

A sample of polyurethane OCMF material measuring 10 mm thick with adensity of approximately 23 kg/m³ was provided. A substantially uniformmixture of 60 g of MDH (fire-class additive) in about 529 mL of ethanol(with up to 10% vol. water) was combined with about 460 mL of silica solfrom Example 1, and stirred for no less than 5 minutes. About 10 mL of28 vol % NH₄OH solution was then added, followed by at least 1 minute ofstirring the sol mixture. The sol mixture was then infiltrated into thepolyurethane OCMF material and allowed to gel, within gelation occurringwithin 2 minutes. The resulting gel composite was allowed to sit andcure for approximately 10 minutes. The gel composite was then aged for16 h at 68° C. in ethanol aging fluid containing 10 vol % H₂O and 1.1wt/vol % NH₄OH (1.1 g of NH₄OH per 100 mL of fluid) at a fluid to gelcomposition ratio of about 1.5:1.

The gel composition coupons (samples) were then subjected to solventextraction by way of supercritical CO₂ and then dried at 120° C. for 4hours. Target silica density was 0.06 g/cc, and the resulting materialdensity of the aerogel composition was 0.165 g/cc. The hydrophobecontent of the aerogel composition was about 3.95 wt %.

Example 11

Polyethylsilicate sol was produced by hydrolyzing TEOS in EtOH and H₂Owith sulfuric acid catalyst, and was then stirred at ambient temperaturefor no less than 16 h. Polymethylsilsesquioxane sol as produced byhydrolyzing MTES and DIVIDES (about 8:1 molar ratio) in EtOH and H₂Owith acetic acid catalyst, and was then stirred at ambient temperaturefor no less than 16 hours. Polyethylsilicate (TEOS) andpolymethylsilsesquioxane (MTES+DMDES) sols were combined (about 10:1weight ratio) to form a silica sol which targeted a sol hydrophobecontent of about 12 wt % in the final aerogel composition. The combinedsilica sol was stirred at ambient temperature for no less than 2 hours.

Example 12

A sample of melamine OCMF material measuring 10 mm thick with a densityof approximately 6 kg/m³ was provided. A substantially uniform mixtureof 60 g of MDH (fire-class additive) in about 718 mL of ethanol (with upto 10% vol. water) was combined with about 266 mL of silica sol fromExample 11, and stirred for no less than 5 minutes. About 10 mL of 28 wt% NH₄OH solution was then added, followed by at least 1 minute ofstirring the sol mixture. The sol mixture was then infiltrated into themelamine OCMF material and allowed to gel, within gelation occurringwithin 2 minutes. The resulting gel composite was allowed to sit andcure for approximately 10 minutes. The gel composition was then treatedfor 16 h at 68° C. in ethanol containing 0.12M trimethlysilylderivatives of hexamethyldisilazane (“TMS”), 8 vol % H₂O and 0.8 g ofNH₄OH₃ per 100 mL of ethanol at a fluid to gel composition ratio ofabout 1.5:1.

The gel composition coupons where then subjected to solvent extractionby way of supercritical CO₂ and then dried at 120° C. for 4 hours.Target silica density was 0.05 g/cc, and the resulting material densityof the aerogel composition was 0.176 g/cc.

Example 13

A gel composition was produced using the same procedure as Example 12,except a substantially uniform mixture of about 718 mL of ethanolsolvent (no fire-class additive) was combined with about 256 mL ofsilica sol from Example 8. Target silica density was 0.05 g/cc, and theresulting material density of the aerogel composition was 0.081 g/cc.

Example 14

A gel composite material was produced using the same procedure asExample 11, except the polyethylsilicate (TEOS) andpolymethylsilsesquioxane (MTES+DMDES) sols were combined at about 7:1weight ratio to form a silica sol which targeted a 16 wt % of totalhydrophobe content in the final aerogel composition.

Example 15

A gel composition was produced using the same procedure as Example 12,except a substantially uniform mixture of 72 g of MDH (fire-classadditive) in about 668 mL of ethanol solvent was combined with about 317mL of silica sol from Example 14. Target silica density was 0.06 g/cc,and the resulting material density of the aerogel composition was 0.195g/cc. Using thermogravimetric curves, the onset of thermal decompositionwas found to be 399.5° C., and using DSC curves, the temperature of peakheat release was found to be 439.6° C. The extrapolated onset of thermaldecomposition of the composition including the fire-class additive wasmeasured using thermogravimetric curves as 395.8° C., and thetemperature of peak heat release was measured using DSC curve as 560.9°C.

For comparison, a composition within this example without any fire-classadditive was found to have an extrapolated onset of thermaldecomposition of 369.4° C., as measured using thermogravimetric curves,and the temperature of peak heat release was found to be 607.9° C., asmeasured using DSC curves.

Example 16

A gel composition was produced using the same procedure as Example 12,except a mixture of about 668 mL of ethanol solvent (no fire-classadditive) was combined with about 317 mL of silica sol from Example 14.Target silica density was 0.06 g/cc, and the resulting material densityof the aerogel composition was 0.092 g/cc.

Example 17

Polyethylsilicate sol was produced by hydrolyzing TEOS in ethanol andwater with sulfuric acid catalyst, and was then stirred at ambienttemperature for about 16 hours. This hydrophobe-free sol was usedwithout the addition of any polymethylsilsesquioxane sol or otherhydrophobic material.

Example 18

A gel composite material was produced using the same procedure asExample 12, except a mixture of about 662 mL of ethanol solvent (nofire-class additive) was combined with about 328 mL of silica sol fromExample 17 and allowed to gel. The gel was treated with a solutioncontaining 0.3 M TMS in ethanol (8 vol % H₂O and 0.8 g NH₄OH per 100 mLof ethanol at a fluid to gel composite ratio of about 1.5:1) for 16hours at 68° C. Target silica density was 0.06 g/cc, and the resultingmaterial density of the aerogel composite was 0.086 g/cc.

Example 19

A gel composite material was produced using the same procedure asExample 12, except a mixture of about 662 mL of ethanol solvent (nofire-class additive) was combined with about 328 mL of silica sol fromExample 17 and allowed to gel. The gel was treated with a solutioncontaining 0.6 M MTES (8 vol % H₂O and 0.8 g NH₄OH per 100 mL of ethanolat a fluid to gel composite ratio of about 1.5:1) for 16 hours at 68° C.Target silica density was 0.06 g/cc, and the resulting material densityof the aerogel composite was 0.103 g/cc.

Example 20

A gel composite material was produced using the same procedure asExample 2, except a substantially uniform mixture of 112 g of halloysiteclay (fire-class additive; DRAGONITE) in about 453 mL of ethanol (withup to 8% vol. water) was combined with about 537 mL of silica sol fromExample 1. Target silica density was 0.07 g/cc, and the resultingmaterial density of the aerogel composite was 0.196 g/cc. The hydrophobecontent of the aerogel composition was about 3.37 wt %.

Example 21

A gel composite material was produced using the same procedure asExample 2, except a substantially uniform mixture of 72 g of halloysiteclay (fire-class additive; DRAGONITE) in about 529 mL of ethanol (withup to 10% vol. water) was combined with about 460 mL of silica sol fromExample 1. Target silica density was 0.06 g/cc, and the resultingmaterial density of the aerogel composite was 0.128 g/cc. The hydrophobecontent of the aerogel composition was about 3.91 wt %. The onset ofthermal decomposition was measured using thermogravimetric curves as492.9° C., and the temperature of peak heat release was measured usingDSC curve as 565.9° C. The extrapolated onset of thermal decompositionof the composition including the fire-class additive was measured usingthermogravimetric curves as 370.9° C., and the temperature of peak heatrelease was measured using DSC curve as 565.9° C.

For comparison, a composition within this example without any fire-classadditive was found to have an extrapolated onset of thermaldecomposition of 369.4° C., as measured using thermogravimetric curves,and the temperature of peak heat release was found to be 607.9° C., asmeasured using DSC curves.

Example 22

A gel composite material was produced using the same procedure asExample 2, except a substantially uniform mixture of two fire-classadditives-36 g of halloysite clay (DRAGONITE) and 36 g of aluminatrihydrate (ATH)—in about 529 mL of ethanol (with up to 10% vol. water)was combined with about 460 mL of silica sol from Example 1. Targetsilica density was 0.06 g/cc, and the resulting material density of theaerogel composite was 0.149 g/cc. The hydrophobe content of the aerogelcomposition was about 3.94 wt %.

Example 23

A gel composite material was produced using the same procedure asExample 2, except a substantially uniform mixture of 72 g of aluminatrihydrate (ATH) in about 529 mL of ethanol (with up to 10% vol. water)was combined with about 460 mL of silica sol from Example 1. Targetsilica density was 0.06 g/cc, and the resulting material density of theaerogel composite was 0.152 g/cc. The hydrophobe content of the aerogelcomposition was about 3.94 wt %. Using thermogravimetric curves, theonset of thermal decomposition was measured as 289.8° C., and thetemperature of peak heat release was measured using DSC curve as 334.1°C.

For comparison, a composition within this example without any fire-classadditive was found to have an extrapolated onset of thermaldecomposition of 369.4° C., as measured using thermogravimetric curves,and the temperature of peak heat release was found to be 607.9° C., asmeasured using DSC curves.

Example 24

A gel composite material was produced using the same procedure asExample 12, except a substantially uniform mixture of 100 g ofhalloysite clay (DRAGONITE) in about 558 mL of ethanol (with up to 10%vol. water) was combined with about 426 mL of silica sol from Example11, which had been combined in such a manner to target 28 wt %hydrophobe content. Target silica density was 0.083 g/cc, and theresulting material density of the aerogel composite was 0.184 g/cc.

Example 25

A gel composition was produced using the same procedure as Example 2,except a substantially uniform mixture of 56 g of halloysite clay(DRAGONITE from Applied Minerals, Inc.) and 56 g of ATH in about 453 mLof ethanol (with up to 8% vol. water) was combined with about 537 mL ofsilica sol from Example 1. Target silica density was 0.07 g/cc, and theresulting material density of the aerogel composite was 0.196 g/cc. Thehydrophobe content of the aerogel composition was about 3.36 wt %.

Table 1 is presented below, illustrating the composition of theforegoing examples. The term “wt % loading” refers to the amount ofadditive loaded into the composition based on the amount of silicapresent. For example, a “wt % loading” of 120% indicates that for every100 g of silica in the composition, 120 g of additive is loaded.

TABLE 1 Composition from examples. Target Sol Silica Example HydrophobeDensity wt % # Content (%) (g/cc) Additive Type Loading 2 36 0.07 MDH100 3 36 0.06 MDH 120 4 36 0.08 MDH 120 5 36 0.06 MDH 140 6 36 0.06 None0 7 36 0.06 Inert Glass Beads 120 8 36 0.06 Wollastonite 120 9 36 0.06Titanium dioxide 120 10 36 0.06 MDH 120 12 12 0.05 MDH 120 13 12 0.05None 0 15 16 0.06 MDH 120 16 16 0.06 None 0 18 0 0.06 None 0 19 0 0.06None 0 20 36 0.07 Halloysite clay 160 21 36 0.06 Halloysite clay 120 2236 0.06 Halloysite clay + ATH 120 23 36 0.06 ATH 120 24 28 0.083Halloysite clay 120 25 36 0.07 Halloysite clay + ATH 160

Table 2 presents measurements of density, TC, liquid water uptake, HOC,FTR, flame time, and mass loss for the exemplary composites of Table 1.

TABLE 2 Resulting properties from examples. Composite TC Liquid WaterHOC Furnace Temp Flame Mass Loss Example # Density (g/cc) (mW/m-K)Uptake (wt %) (cal/g) Rise (° C.) Time (s) (wt %) 2 0.159 18.6 4.4 670.432 0 28.8 3 0.185 20.1 5.1 492.7 35.5 0 44.1 4 0.178 17.8 5.6 584.7 40.10 19.1 5 0.142 18.4 2.8 668.6 32.7 0 17.7 6 0.074 15.2 8.5 1599.9 194.881 18.1 7 0.141 19.5 6.4 714.8 81.7 120 10.9 8 0.161 19.6 4.6 616 41.113 20.7 9 0.159 16.1 4.2 797 45 35 43.6 10 0.165 19.2 2.0 1196 81 5038.5 12 0.176 15.5 4.5 684.1 44.9 0 47.6 13 0.081 14.8 3.7 1920.6 153.976 26.5 15 0.195 18.5 8.8 486.1 41.8 0 34.9 16 0.092 14.7 3.1 1886.9 112110 16.6 18 0.086 14.2 4.5 1966 178.9 100 18.0 19 0.103 14.9 26.1 143395.1 109 15.3 20 0.196 17.2 4.8 621 10.0 0 17.8 21 0.128 17.7 3.7 74740.2 5 16.1 22 0.149 16.3 3.8 785 49.3 70 22.2 23 0.152 16.4 3.1 73334.0 33 27.2 24 0.184 15.7 2.3 783 38.8 0 19.6 25 0.184 18.5 <5 600 9.310 22.4

Still referring to Table 2, density measurements were completedaccording to ASTM C167. All aerogel composition samples had measureddensities below 0.2 g/cc. TC measurements were completed according toASTM C518 at a temperature of about 37.5° C. and a compression of 2 psi.All aerogel composition samples had thermal conductivity measurements ator below 20.1 mW/m-K. Measurements of liquid water uptake were madeaccording ASTM C1511 (under 15 minute submersion in ambient conditions).All aerogel composition samples had a liquid water uptake below 5 wt %.HOC measurements were made per ISO 1716 measurement standards. Allaerogel composition samples had a HOC below 690 cal/g. FTR measurementswere made per ISO 1182 Criterion A.1. All aerogel composition sampleshad a FTR below 50° C. Flame time measurements were made per ISO 1182Criterion A.2. All of these samples had a measured flame time of 20seconds. Mass Loss measurements were completed according to ISO 1182Criterion A.3. All other aerogel composition samples had a mass lossbelow 50 wt %.

The advantages set forth above, and those made apparent from theforegoing description, are efficiently attained. Since certain changesmay be made in the above construction without departing from the scopeof the invention, it is intended that all matters contained in theforegoing description or shown in the accompanying drawings shall beinterpreted as illustrative and not in a limiting sense.

It is also to be understood that the following claims are intended tocover all of the generic and specific features of the invention hereindescribed, and all statements of the scope of the invention that, as amatter of language, might be said to fall therebetween.

What is claimed is:
 1. A reinforced aerogel composition comprising: areinforced silica-based aerogel material that includes: a reinforcementmaterial comprising an open-cell macroporous framework (OCMF) material;a silica-based aerogel material incorporated with the reinforcementmaterial; and an endothermic fire-class additive incorporated with thereinforced aerogel composition; wherein: the reinforced silica-basedaerogel material has an onset of thermal decomposition temperature; andthe endothermic fire-class additive has an onset of thermaldecomposition temperature that is within 50° C. of the onset of thermaldecomposition temperature of reinforced silica-based aerogel material.2. The reinforced aerogel composition of claim 1, wherein theendothermic fire-class additive is present in the reinforced aerogelcomposition in about 5 wt % to 70 wt %.
 3. The reinforced aerogelcomposition of claim 1, wherein the OCMF material comprises a melaminebased OCMF material.
 4. The reinforced aerogel composition of claim 1,wherein the OCMF material comprises a sheet of OCMF material.
 5. Thereinforced aerogel composition of claim 1, wherein the OCMF materialcomprises a foam material.
 6. The reinforced aerogel composition ofclaim 1, wherein the reinforced silica-based aerogel material furthercomprises a hydrophobe.
 7. The reinforced aerogel composition of claim6, wherein the OCMF material comprises a flammable material, acombustible material, or both.
 8. The reinforced aerogel composition ofclaim 1, wherein the reinforced aerogel composition has an onset ofthermal decomposition of from 280° C. to 390° C.
 9. The reinforcedaerogel composition of claim 1, wherein the endothermic fire-classadditive comprises halloysite clay.
 10. The reinforced aerogelcomposition of claim 1, wherein the endothermic fire-class additive doesnot include kaolin or hydrated alumina.
 11. The reinforced aerogelcomposition of claim 1, wherein the onset of thermal decompositiontemperature of the endothermic fire-class additive corresponds todehydration or dihydroxylation.
 12. The reinforced aerogel compositionof claim 1, wherein the reinforced aerogel composition is characterizedby: i) a liquid water uptake of 20 wt % or less; ii) a thermalconductivity of 30 mW/M*K or less according to ASTM C518 standard at atemperature of about 37.5° C., in an ambient environment, at atmosphericpressure, and at a compression load of about 2 psi;
 13. A reinforcedaerogel composition comprising: a reinforced silica-based aerogelmaterial that includes: a reinforcement material comprising an open-cellmacroporous framework (OCMF) material; a silica-based aerogel materialincorporated with the reinforcement material; and an endothermicfire-class additive incorporated with the reinforced aerogelcomposition; wherein: the reinforced silica-based aerogel material has afirst exothermic heat of decomposition; and the endothermic fire-classadditive has a second exothermic heat of decomposition that is at least30% of the first exothermic heat of decomposition.
 14. The reinforcedaerogel composition of claim 13, wherein the endothermic fire-classadditive is present in the reinforced aerogel composition in about 5 wt% to 70 wt %.
 15. The reinforced aerogel composition of claim 13,wherein the OCMF material comprises or is a melamine based OCMFmaterial.
 16. The reinforced aerogel composition of claim 13, whereinthe OCMF material comprises a sheet of OCMF material.
 17. The reinforcedaerogel composition of claim 13, wherein the OCMF material comprises afoam material.
 18. The reinforced aerogel composition of claim 13,herein the reinforced silica-based aerogel material further comprises ahydrophobe.
 19. The reinforced aerogel composition of claim 18, whereinthe OCMF material comprises a flammable material, a combustiblematerial, or both.
 20. The reinforced aerogel composition of claim 13,wherein the reinforced aerogel composition has an onset of thermaldecomposition of from 350° C. to 390° C.
 21. The reinforced aerogelcomposition of claim 13, wherein the endothermic fire-class additivecomprises halloysite clay.
 22. The reinforced aerogel composition ofclaim 13, wherein the first exothermic heat of decomposition of thereinforced silica-based aerogel material is from 625 cal/g to 700 cal/gaccording to EN ISO 1716 standard.
 23. The reinforced aerogelcomposition of claim 13, further comprising at least two fire-classadditives, wherein the respective onsets of thermal decomposition of theat least two fire-class additives are at least 10° C. apart.
 24. Thereinforced aerogel composition of claim 13, wherein the endothermicfire-class additive does not include kaolin or hydrated alumina.